Methods of Treating Fragile X Syndrome

ABSTRACT

Subjects having fragile X syndrome are treated with a composition that includes gamma-aminobutyric acid agonists. The gamma-aminobutyric acid agonist (GABA) can be a GABA(B) agonist, such as baclofen, including racemic and R-baclofen.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/454,202, filed May 14, 2009, which is a continuation of InternationalApplication No. PCT/US2007/024311, filed Nov. 21, 2007, which designatesthe U.S., published in English, and claims the benefit of U.S.Provisional Application No. 61/001,567, filed Nov. 2, 2007 and U.S.Provisional Application No. 60/860,733, filed Nov. 22, 2006. The entireteachings of the above applications are incorporated herein byreference.

BACKGROUND OF THE INVENTION

Mental retardation, Down's syndrome, fragile X syndrome and autism aredevelopmental and genetic disorders that affect day to day functioning,including learning, memory, speech, social skills and behavior.Currently available treatment regimens for humans with mentalretardation, Down's syndrome, fragile X syndrome and to assist inday-to-day functioning, include, for example, behavioral modificationsand treatment with a range of medications including anti-depressant andanti-psychotic drugs. However, such regimens frequently are noteffective or may produce undesirable side-effects with long term use,particularly the use of anti-psychotic drugs. Thus, there is a need todevelop new, improved and effective methods to treat mental retardation,Down's syndrome, fragile X syndrome and autism.

SUMMARY OF THE INVENTION

The present invention relates to a method of treating humans havingmental retardation, Down's syndrome, fragile X syndrome and autism.

In one embodiment, the invention is a method of treating a human,comprising the step of administering to a human having at least onecondition selected from the group consisting of Down's syndrome, fragileX syndrome and autism a composition that includes a gamma-aminobutyricacid agonist.

In another embodiment, the invention is a method of treating a human,comprising the step of administering to a human having at least onecondition selected from the group consisting of Down's Syndrome, fragileX syndrome and autism a composition that includes Formula I:

In yet another embodiment, the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes baclofen, wherein the baclofen is administered to the human ata dose of about 2 mg per day for days 1, 2 and 3 of treatment, a dose ofabout 4 mg per day for days 4, 5 and 6 of treatment, a dose of about 6mg per day for days 7, 8 and 9 of treatment, a dose of about 10 mg perday for days 10, 11 and 12 of treatment, a dose of about 20 mg per dayfor days 13, 14 and 15 of treatment, a dose of about 30 mg per day fordays 16, 17 and 18 of treatment and a dose between about 30 mg to about80 mg per day for the duration of the treatment.

In an additional embodiment, the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes baclofen, wherein the baclofen is administered to the human ata dose of about 15 mg for days 1, 2 and 3 of treatment, a dose of about30 mg for days 4, 5 and 6 of treatment, a dose of about 45 mg for days7, 8 and 9 of treatment, a dose of about 60 mg for days 10, 11 and 12 oftreatment and a dose between about 60 mg to about 80 mg per day for theduration of the treatment.

In still another embodiment, the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes at least about 51 mole percent S-baclofen relative to the totalS-baclofen and R-baclofen in the composition administered to the human.

In a further embodiment, the invention is a method of treating a human,comprising the step of administering to a human having at least onecondition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes at least about 51 mole percent R-baclofen relative to the totalR-baclofen and S-baclofen in the composition administered to the human.

An additional embodiment of the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes baclofen, wherein the baclofen is administered to the human ata dosing regimen of at least one member selected from the groupconsisting of about 1 mg twice a day, about 2 mg twice a day, about 3 mgtwice a day, about 5 mg twice a day, about 10 mg twice a day and about10 mg three times a day.

In yet another embodiment, the invention is a method of treating asubject, comprising the step of administering to a subject having atleast one condition selected from the group consisting of mentalretardation, Down's syndrome, fragile X syndrome and autism acomposition that includes at least one M1 muscarinic antagonist.

Advantages of the claimed invention can include, for example, treatmentof mental retardation, Down's syndrome, fragile X syndrome and autism ina manner that can improve symptoms (e.g., reduce anxiety andirritability; increase cognitive function, communication and/or socialinteraction), efficacy or reduce side effects and thereby improvetolerability for use over a relatively long period of time withoutsignificant side effects. The methods of the invention can provide aneffective manner to treat a subject having mental retardation, Down'ssyndrome, fragile X syndrome and/or autism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the effects of racemic baclofen on the inhibition ofmarble-burying behavior in fragile X (Fmr1) knock out (KO) mice (n=7-8mice/group). Data are expressed as the mean±SEM number of marblesburied.

FIG. 2 depicts the effects of R(+)-baclofen on marble-burying behaviorin Fmr1 KO mice (n=10-16 mice/group). Data are expressed as the meanmarbles buried±SEM. An asterik (*) indicates data for the 10 mg/kg dosewas significantly less (p<0.05) than all other groups.

FIG. 3 depicts the effects S(−)-baclofen on marble-burying behavior ofFmr1 KO mice (n=11-15 mice/group). Data are expressed as the mean numberof marbles buried±SEM. The # symbol indicates that the data for the 1mg/kg dose was significantly greater than the 0 mg/kg dose. The asterik(*) indicates that the 50 mg/kg dose was significantly different(p<0.05) than all other groups.

FIG. 4 depicts the effect of R(+)-baclofen and S(−)-baclofen onaudiogenic seizures in Fmr1 KO mice (n=9-10 mice/group). Data areexpressed as a percentage of mice treated with vehicle (0 mg/kg), R(+)-or S(−)-baclofen, that exhibited audiogenic seizures.

FIG. 5 depicts the effect of R(+)- and S(−)-baclofen on open-fieldactivity of Fmr1 KO male mice. Data are expressed as the mean±SEM of thetotal distance traveled. The symbol # indicates that the data for thevehicle treated Fmr1 KO mice are significantly higher than wild type(WT) mice. An asterik (*) indicates that the vehicle-treated Fmr1 KOmice were significantly higher than the respective dose of R(+)- or(S−)-baclofen.

FIG. 6 depicts dicyclomine inhibition of marble-burying behavior infragile X knockout (KO) mice (n=3-5 mice/group). Data are expressed asthe mean number of marbles buried±SEM.

FIG. 7 depicts audiogenic seizures in young Fmr1 KO mice with or withoutdicyclomine (diccyc.) treatment. Data are the percentage of mice treatedwith vehicle (0 mg/kg) or dicyclomine (40 mg/kg) that displayedaudiogenic seizures.

DETAILED DESCRIPTION OF THE INVENTION

The features and other details of the invention, either as steps of theinvention or as combinations of parts of the invention, will now be moreparticularly described and pointed out in the claims. It will beunderstood that the particular embodiments of the invention are shown byway of illustration and not as limitations of the invention. Theprinciple features of this invention can be employed in variousembodiments without departing from the scope of the invention.

In one embodiment, the invention is a method of treating a human,comprising the step of administering to a human having at least onecondition selected from the group consisting of Down's syndrome, fragileX syndrome and autism a composition that includes a gamma-aminobutyricacid (GABA) agonist, such as a GABA(B) receptor agonist (also referredto herein as “GABA(B) agonist” or “GABAB agonist”).

GABA (gamma-amino butyric acid) is an abundant neurotransmitter in themammalian brain. GABA, like other neurotransmitters, includingL-glutamate, serotonin and acetylcholine, activates ionotropic andmetabotropic receptors. Ionotropic receptors are ligand gated ionchannels that convey fast synaptic transmission, whereas G-proteincoupled metabotropic receptors modulate synaptic transmission throughintracellular effector systems. GABA exerts its effects throughionotropic ligand-gated GABA(A) (also referred to as “GABAA”), GABA(C)(also referred to as “GABAC”) and GABA(B) (also referred to as “GABAB”)receptors to produce slow, and prolonged synaptic inhibitory signals byactivating a Cl-conductance that can be allosterically modulated bypsychoactive drugs, such as the benzodiazepines, barbiturates andneurosteroids.

The subunits of the GABA(A) receptor have sequence homology with thenAChR subunit family. A family of GABA(A) receptors subtypes exists,which are generated by alternative splicing of alpha 1-6, beta 1-4,gamma 1-4, delta, epsilon, pie, theta, and rho1-3 to form proteincomplexes. Various GABA(A) subunits show distinct patterns of temporaland spatial expression that may have tissue specific physiologicalroles. GABA(A) receptor proteins are characterized by the presence of acleavable signal peptide, a large extracellular N-terminus, threetransmembrane domains, a large cytoplasmic domain followed by anothertransmembrane domain and C-terminal extracellular domain. The othercommon motif is referred to as a Cys-loop and two Cys loops areseparated by thirteen amino acids in the extracellular domain of thereceptor. The regions between the third and fourth transmembrane domainand the large cytoplasmic loop are least conserved among various GAAsubunits, which may confer subunit specific functionality. GAA genes aredistributed as clusters throughout the human genome (chromosomes 4, 5,15, and X; delta subunit on chromosome 1).

GABA(B) receptors are metabotropic transmembrane receptors forgamma-aminobutyric acid (GABA) that are linked by G-proteins topotassium channels (Chen K, et al., Brain Res Bull 67: 310-8 (2005)).GABA(B) receptors are found in the central and peripheral autonomicnervous system. GABA(B) receptors can stimulate potassium channels,which can result in hyperpolarization of the neuron, prevent sodiumchannel influx and, thus, neurotransmitter release. GABA(B) receptorsmay also reduce adenylyl cyclase activity and decrease calciumconductance in a neuron.

GABA(B) receptors are structurally similar to metabotropic glutamatereceptors and are divided into two subtypes GABA(B)1 and GABA(B)2, whichappear to assemble as heterodimers in neuronal membranes by linking bycarboxy-termini.

An “agonist,” as used herein, is a compound that activates cellsignaling. For example, a GABA(B) receptor agonist activates cellsignaling mediated through GABA(B) receptors and an α2-adrenergicagonist activates cell signaling mediated through α2-adrenergicreceptors.

The GABA agonists employed in the methods of the invention preferablycross the blood brain barrier. The GABA agonists for use in the methodsdescribed herein can inhibit glutamate release in the central nervoussystem, such as in the cortex and basal ganglia of the central nervoussystem.

In another embodiment, the invention is a method of treating a human,comprising the step of administering to a human having at least onecondition selected from the group consisting of mental retardation,Down's Syndrome, fragile X syndrome and autism a composition thatincludes Formula I:

Formula I is baclofen, which is also referred to asβ-(Aminomethyl)-4-chlorobenzenepropanoic acid;β-(aminomethyl)-p-chlorohydrocinnamic acid;γ-amino-β-(p-chlorophenyl)butyric acid; 3-(4-chlorophenyl)GABA. Baclofenis also referred to as Baclon, Lioresal, Kemstro and Myospan.

The methods of the invention can include the use of a GABA(B) receptoragonist in combination with, for example, Formula II:

Formula II is 2-amino-6-trifluormethoxybenzothiazole and is alsoreferred to herein as “riluzole” (see, for example, U.S. Pat. No.4,370,338, the teachings of which are hereby incorporated by referencein its entirety).

Formula II is FDA approved for the treatment of amyotrophic lateralsclerosis. It has multiple activities, including inhibition ofpresynaptic glutamate release by inactivation of P/Q-type calciumchannels, enhancement of glutamate uptake in astrocytes, and inhibitionof voltage-dependent sodium channels in mammalian CNS neurons. It hasalso been reported to potentiate AMPA/KA receptor-mediated transmission,as well as enhance brain-derived neurotrophic factor. Riluzole has beenshown to have neuroprotective, anticonvulsant activity, anti-anxietyactivity, and antidepressant activity in animal models and in humans.

The subject can be treated with salts (e.g., acid salts, base salts,HCl, oxaylate, calcium, sodium, magnesium, lithium), prodrugs,polymorphs and other structural and functional derivatives thereof ofthe compounds, such as Formulas I and II, described herein.

Mental retardation means that a subject has lower than averageintelligence. Intelligence describes a subject's ability to think, learnand solve problems. A subject with mental retardation may havedifficulty learning, may take longer to learn social skills, such as howto communicate, and may be less able to care for himself or herself andto live on his or her own as an adult.

Down's syndrome is a disorder that includes a combination of birthdefects, including some degree of mental retardation, characteristicfacial features and, often, heart defects, increased infections,problems with vision and hearing, and other health problems. Theseverity of these problems varies greatly among affected subjects.Down's syndrome is generally is caused by an extra copy chromosome 21and is also referred to as trisomy 21.

The fragile X syndrome, as implied by its name, is associated with afragile site expressed as an isochromatid gap in the metaphasechromosome at map position Xq 27.3. Fragile X syndrome is a geneticdisorder caused by a mutation in the 5′-untranslated region of thefragile X mental retardation 1 (FMR1) gene, located on the X chromosome.The mutation that causes fragile X syndrome is a associated with a CGGrepeat in the fragile X mental retardation gene FMR-1. When a subjecthas more than about 200 CGG repeats, the fragile X gene ishypermethylated, silenced, fragile X mental retardation protein (FMRP)is not produced and the subject is diagnosed as having fragile Xsyndrome (See, for example, U.S. Pat. Nos. 6,107,025 and 6,180,337, theentire teachings of both of which are hereby incorporated by referencein their entirety).

The fragile X syndrome segregates as an X-linked dominant disorder withreduced penetrance. Either sex when carrying the fragile X mutation mayexhibit mental deficiency, which is variable in severity.

Children and adults with fragile X syndrome have varying degrees ofmental retardation or learning disabilities and behavioral and emotionalproblems, including autistic-like features and tendencies. Youngchildren with fragile X syndrome often have delays in developmentalmilestones, such as learning how to sit, walk and talk. Affectedchildren may have frequent tantrums, difficulties in paying attention,frequent seizures (e.g., temporal lobe seizures) are often highlyanxious, easily overwhelmed, can have sensory hyperarousal disorder,gastrointestinal disorders, may have speech problems and unusualbehaviors, such as hand flapping and hand biting.

Fragile X syndrome can be diagnosed by an established genetic testperformed on a sample (e.g., blood sample, buccal sample) from thesubject. The test determines whether a mutation or pre-mutation ispresent in the FMR-1 gene of the subject.

Subjects with fragile X syndrome can also have autism, attentiondeficient disorder and/or obsessive compulsive disorder. Fragile Xsyndrome is a prevalent form of inherited mental retardation and ischaracterized by developmental delay, hyperactivity, attention deficitdisorder and autistic-like behaviors (Jin, P., et al., Hum Mol Genet 9:901-908 (2000)).

About 5% of all children diagnosed with autism have a mutation in theFMR1 gene and also have fragile X syndrome (FXS). About 15 to about 20%of subjects with fragile X syndrome meet the full diagnostic criteriafor autism. Although mental retardation is a hallmark feature of fragileX syndrome, subjects with fragile X syndrome often display autisticfeatures ranging from shyness, poor eye contact, and social anxiety inmild cases to hand flapping, hand biting and preservative speech in theseverely affected. Subjects with fragile X syndrome display othersymptoms associated with autism such as attention deficit andhyperactivity, seizures, hypersensitivity to sensory stimuliobsessive-compulsive behavior and altered gastrointestinal function. TheFMR1 mutation prevents expression of a single protein (FMRP). Braindevelopment in the absence of FMRP gives rise to the major symptoms offragile X syndrome. A key tool allowing for a better understanding ofthe function of FMRP has been development of the Fmr1 knockout mouse.

In addition to core symptoms, children with fragile X syndromefrequently have serious behavioral disturbances such as irritability,aggression and self-injurious behaviors. In a recent study of males withfragile X syndrome (ages 8-24), self-injurious behavior was reported in79%, and aggressive behavior in 75%, of subjects during a two monthobservation period (Hessl, D., et al., The National Fragile X FoundationQuarterly, Issue 25:10-13 (2006)). Despite the common occurrence ofirritable, aggressive and self-injurious behavior in subjects withfragile X syndrome, there has been little research assessing treatmentsfor these symptoms.

Although there has been little research in subjects with fragile Xsyndrome, serious behavioral disturbances such as self-injuriousbehavior, aggression and tantrums occur frequently in individuals withautism (McCracken, J. T., et al., N Engl. J. Med. 347:314-321 (2002)),and there have been numerous clinical trials assessing a variety oftherapeutic treatments. Behavior therapy may provide benefits, but ishighly individualized and has not been evaluated in randomized clinicaltrials (Schreibman, L., J. Autism Dev. Discord. 5:373-378 (2002)).Similarly, treatments with several medications in various chemicalclasses have had limited success (McDougle, C. J., et al., ChildAdolesc. Psychiatr. Clin. N. Am. 9:201-224 (2002)). Risperidone, anatypical antipsychotic, has been used to treat behaviors in subjectswith autism (McCracken, J. T., et al., N. Engl. J. Med. 347:314-321(2002)). However, risperidone produces a number of undesirable sideeffects including increased appetite (73%) and weight gain (2.7 kg over8 weeks), fatigue (59%), drowsiness (49%), drooling (27%), and dizziness(16%) (McCracken, J. T., et al., N. Engl. J. Med. 347:314-321 (2002)).There are also unresolved safety concerns that long-term therapy maycause extrapyramidal symptoms and that elevated prolactin levels mayaffect growth and sexual maturation. These side effects limittolerability and usefulness of risperidone alone for treating irritableaberrant behavior in subjects with autism.

Formal studies have not been published in subjects with fragile Xsyndrome, however clinical experience with atypical antipsychotics, suchas risperidone alone is consistent with the results observed in subjectswith autism (McCracken, J. T., et al., N. Engl. J. Med. 347:314-321(2002); Berry-Kravis, E., et al., Ment. Retard. Devel Disabil. Res. Rev.10:42-48 (2004)). Specifically, risperidone alone reduces irritablebehavior, but the side effect profile limits use of it alone in subjectswith fragile X syndrome.

Initial studies of the behavioral phenotype of the Fmr1 KO mouse on amixed genetic background reported that the Fmr1 KO mice displayedincreased exploratory and locomotor activity compared to wild-typecontrols, and also a slight learning impairment in the Morris water maze(Bakker, C. E., et al., Cell 78:23-33 (1994)). This learning impairmenthas been further analyzed by several groups using the Morris water task,plus-shaped water maze, operant conditioning paradigms, conditionedfear, passive avoidance and the radial maze (Bakker, C. E., et al., Cell78:23-22 (1994). Fmr1 KO mice have impaired learning processes whenassessed on assays that had previously not been attempted. Fmr1 KO micedo have impaired learning that is clearly task dependent. It is likelythat learning and memory performance of Fmr1 KO mice is dependent ongenetic background (Paradee, W., et al., Neuroscience 94:185-192(1999)). Although the learning and memory phenotype of the Fmr1 KO mousehas been challenging and somewhat elusive, there are sufficient dataindicating that Fmr1 KO mice are hyperactive, have altered responses ontests of anxiety, and altered sensorimotor gating (Mineur, Y. S., etal., Hippocampers 12:39-46 (2002)). FMRP can regulate behavioral statesof activity/arousal, anxiety-related responses, and social interactions(Bakker, C. E., et al., Cell 78:23-33 (1994); Peier, A. M., et al., Hum.Mol. Genet 9:1145-1159 (2000)).

By challenging the Fmr1 KO mice with different test situations, the KOmice are hyperactive, can display increased anxiety-like responses, doshow abnormal social interactions, and have poor learning and memory.Fmr1 KO mice display several abnormal behavioral responses that parallelsymptoms of FXS. Behavioral responses of Fmr1 KO mice depend on geneticbackground. Fmr1 KO mice on particular genetic backgrounds displayincreased ‘autistic-like’ traits. Specifically, Fmr1 KO mice on aC57BL/6J X DBA/2 F1 (D2-Fmr1 F1) hybrid background display increasedstereotypes in the open-field, increased obsessive-like responding inthe marble-burying task, and have reduced social interactions, whileFmr1 KO mice on a C57BL/6J X 129S1/SvImJ F1 (129-Fmr1 F1) hybridbackground appear to have poor social recognition. That only some of theFmr1 KO strains display increased ‘autistic-like’ traits is consistentwith the observations that only 15-20% of FXS individuals have autism,and may have variation in FXS due to genetic background. Other mousemodels of FXS can display unique autistic-like features. (Spencer, C.M., et al., Genes, Brain and Behavior, 4:420-430 (2005)).

Cognitive behavioral therapy has been used to improve language andsocialization in fragile X syndrome and autism. In addition, manyclasses of psychiatric drugs are used in clinical practice to treatsymptoms and behavior in both populations (Berry-Kravis, E. et al.,Ment. Retard. Devel Disabil. Res. Rev. 10:42-48 (2004); Malone, R. P.,et al., CNS Drugs 19:923-924 (2005)). In recent years, pharmacologicaltreatment with the atypical antipsychotic risperidone has been commonlyemployed to augment non-pharmacological approaches in the treatment ofindividuals with autism. A randomized placebo-controlled trial ofrisperidone in autistic children demonstrated significant improvement onthe irritability subscale of the Aberrant Behavior Checklist and theClinical Global Impressions-Improvement (McCracken, J. T., et al., N.Engl. J. Med. 347:314-321 (2002)). However, adverse events includedweight gain, increased appetite, fatigue, drowsiness, dizziness, anddrooling. Social isolation and communication were not improved byadministration of risperidone and adverse side effects such asextrapyramidal symptoms and dyskinesias have been associated withrisperidone use in autistic children (Malone, R. P., et al., J. Am.Acad. Child Adolsecent. Psychiatry 41:140-147 (2002)).

Although a number of other drugs, including antipsychotics,antidepressants, and anticonvulsants have mixed results in treatingvarious symptoms and behaviors associated with autism and fragile xsyndrome; there is a need to develop new treatments.

As described herein, R-baclofen may be more potent than S-baclofen forreducing obsessive-compulsive and repetitive behavior, and for reducingaudiogenic seizures, with minimal side effects. R-baclofen may be usefulfor the management of typical problem behavior, such as irritability andaggression, in humans with fragile X syndrome. Baclofen may improveirritable aberrant behavior and also have an improved safety andtolerability profile over atypical antipsychotics in the treatment offragile X syndrome and/or autism. Baclofen may be used in combinationwith other medications, such as risperidone, antipsychotics, Group ImGluR antagonists and M1 muscarinic receptor antagonists.

The pharmacokinetics of baclofen and muscarinic M1 antagonists, such asdicyclomine, in mice to define systemic exposure can be assessed.

Marble burying behavior in rats is considered to be a model ofobsessive-compulsive disorder (OCD) in humans (Matushita, M., et al.,Med. Bull. Fukuoka Univ. 32:159-165 (2005)). Data described herein showthat baclofen inhibits marble-burying behavior.

Subjects with autism can have several symptoms that can range from mildto severe. Such symptoms can include difficulties interacting withothers; making friends; communication problems, both with spokenlanguage and nonverbal gestures; insistence on sameness; and some degreeof mental retardation or learning disabilities in most, but not all, ofaffected children. Subjects with a mild autistic spectrum disorder,referred to as Asperger syndrome, can share some of the features ofautism, have normal intelligence and can learn to speak at the expectedage. Autism is generally diagnosed by observing the behavior of thechild and screening tests that assess a number of characteristics andbehaviors associated with autism. Subjects with autism can also have,for example, obsessive compulsive behaviors, sleep disorders and/orgastrointestinal disorders.

A broad range of psychiatric drugs are used to treat symptoms andimprove behavior in subjects with autism. Antipsychotics are commonlyused to treat moderate to severe behavioral problems associated withautism. Risperidone, an atypical antipsychotic that is used to treataggression, hyperactivity, and other disorders associated with autisticbehavior and aberrant behaviors in fragile X syndrome, can be used incombination with the GABA agonists, M1 muscarinic receptor antagonistsand Group I mGluR antagonists in the methods described herein.Antagonism of the 5-HT_(2A) and D₂ receptors is considered to be crucialfor efficacy of the atypical antipsychotics in schizophrenia, withhigher occupancy of the 5-HT_(2A) receptor versus D₂ being the key todecreased movement side effects. Although all of the atypicalantipsychotics share these two pharmacological actions, they differ byhaving varying activity at other serotonin and dopamine receptors.

Perospirone, an atypical antipsychotic drug approved in Japan fortreatment of schizophrenia, has pharmacologic properties that aredifferent from risperidone, and may be useful in the treatment ofautism, mental retardation and fragile X syndrome. Perospirone's activemetabolite, hydroxyperospirone, has a pharmacologic profile that may beuseful to treat anxiety and obsessive-compulsive behavior. For example,hydroxyperospirone achieves relatively high plasma concentrations thatare acceptable safety and tolerability levels in humans, and may make asignificant contribution to the efficacy observed during treatment withperospirone.

Recent characterization of mutant mice that model human genetic diseaseand display ‘autistic-like’ traits provides an opportunity to evaluatepharmacologic interventions on genetically induced and wellcharacterized ‘autistic-like’ behaviors.

Autism is a disorder characterized by impairments in social interactionand communication, as well as restricted, repetitive and stereotypedpatterns of behavior, interests and activities (DSM-IV). The etiology ofautism can be medically diagnosed for a less than 10% of individuals andfor many of these the diagnosis is attributable to single-gene deficitssuch as fragile X syndrome, neurofibromatosis or tuberous sclerosis.There is considerable evidence that the remaining cases of “idiopathic”autism represent a largely heritable disorder. Twin studies and datafrom whole-genome screens suggest that interactions between at least 10genes predispose to development of autism. Furthermore, it appears thatepigenetic and environmental factors contribute to variable expressionin those genetically predisposed. The complex interaction of genetic andnon-genetic factors in the etiology of “idiopathic” autism has hindereddevelopment of representative animal models and development of newpharmaceutical treatments.

In contrast to the complexity of “idiopathic” autism, a number of humanmonogenic syndromes have a high incidence of autism. Animal models for anumber of these human monogenic syndromes are available. These animalmodels of single gene defects are providing new insights for potentialpharmaceutical treatments for diseases such as neurofibromatosis andfragile X syndrome. Fragile X syndrome (Fmr 1) knockout mice, whichmodel the single gene defect in the human fragile X syndrome, are used.Some of these mice, as well as some humans with fragile X syndrome, haveautistic behaviors.

The methods of the invention can be employed to treat additionalconditions that can be associated with autism or fragile X syndrome, forexample, Coffin-Lowry syndrome, Cohen syndrome, Duchenne/Becker musculardystrophies, Neurofibromatosis, Joubert syndrome, Lujan-Fryns syndrome,PTEN mutations, Noonan syndrome, Orstavik syndrome, ARX mutations,CHARGE, Angelman syndrome, Nance-Horan syndrome, Prader-Willi syndrome,Cerebral dysgenesis and Smith-Lemli-Optiz syndrome.

The methods of the invention can be employed to treat pervasivedevelopmental disorders with no identified source and autism and otherdisorders of brain development.

The methods of the invention can also be employed to treat disorders ofbrain development including Autism Spectrum Disorders (PervasiveDevelopmental Disorders), Rett's syndrome, Childhood DisintegrativeDisorder, Asperger syndrome and Tuberous Sclerosis.

The methods of the invention can be employed to treat deficits/symptoms,for example, deficits in learning, memory, executive function, attentionand/or processing speed. Such deficits can be deficits associated withor observed in subjects with mental retardation, fragile X syndrome,Down's syndrome and autism; and pervasive developmental disorders,including pervasive developmental disorders with no obvious source.

The methods of the invention can be employed to treat neuropsychiatricdisorders and anxiety disorders, including anxiety disorders that areassociated with or observed in subjects that have mental retardation,autism, Down's syndrome and fragile X syndrome. Such anxiety disordersinclude, for example, specific phobias, such as phobias of the doctorand dentist; agoraphobia and separation anxiety. Such disorders can alsoinclude, for example, bipolar disorders, repetitive and stereotypedbehavior, obsessive and compulsive traits/disorders, aggressivebehavior, schizophrenia, hyperactivity, pain, itching, sensoryhyperarousal, seizures, behavioral problems, sleep disorders (includinginsomnia, hypersomnia and abnormal behaviors during sleep).

The methods of the invention can also be employed to treatgastrointestinal disorders and metabolic disorders in subjects withmental retardation, fragile X syndrome, Down's syndrome and autism.Autistic behavior (deficits in social interaction, verbal and non-verbalcommunication, and restricted/repetitive behaviors or interests) insubjects with autism, mental retardation, fragile X syndrome and Down'ssyndrome can also be treated by the methods of the invention.

The human administered the GABA agonist, in particular a GABA(B) agonist(e.g., baclofen), can further be administered (e.g., before,concomitantly, sequentially or after) at least one member selected fromthe group consisting of an antidepressant, a α2-adrenergic agonist, ananticonvulsant, a nicotinic receptor agonist, an endocannabinoidreceptor agonist, an anticonvulsant, and anti-psychotic, an AMPAagonist, a M1 muscarinic antagonist and a Group I mGluR antagonist.

The methods of the invention can be employed to treat fragileX-associated tremor/ataxia syndrome (FXTAS) and movement disorders. Asdiscussed above, an excess of about 200 CGG repeats in the5′-untranslated region of the FMR1 gene results in transcriptionalsilencing of the FMR1 gene and fragile X syndrome. Subjects withpermutation expansions (about 55 to about 200 CGG repeats in the FMR1gene) are generally unaffected intellectually and may develop FXTAS,which is characterized by progressive cerebellar ataxia, parkinsonism,dementia and autonomic dysfunction (Baba, Y., et al., Current Opinion inNeurology 18:393-398 (2005), the teachings of which are herebyincorporated by reference in its entirety).

One of skill in the art would be able to employ well-establishedcriteria to diagnosis a subject that has mental retardation, Down'ssyndrome, fragile X syndrome and autism and the conditions or deficitsdescribed herein. (See, for example, Patzold, L. M., et al., J.Paediatr. Child Health, 34:528-533 (1998); Malow, B. A., Ment. RetardDev. Disabil. Res. Rev. 10:122-125 (2004); Robinson, A. M., et al.,Child Care Health Dev. 30:139-150 (2004); Couturier, J. L., et al., J.Am. Acad Child Adolesc Psychiatry 44:815-822 (2005); Kuddo, T., et al.,Curr. Opin. Pediatr. 15:339-343 (2003); Molloy, C. A., et al., Autism7:165-171 (2003)).

Humans with fragile X syndrome treated by the methods described hereincan also have autism.

In an additional embodiment, the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes baclofen, wherein the baclofen is administered to the human ata dose of about 15 mg for days 1, 2 and 3 of treatment, a dose of about30 mg for days 4, 5 and 6 of treatment, a dose of about 45 mg for days7, 8 and 9 of treatment, a dose of about 60 mg for days 10, 11 and 12 oftreatment and a dose between about 60 mg to about 80 mg per day for theduration of the treatment.

In yet another embodiment, the invention is a method of treating ahuman, comprising administering to a human having at least one conditionselected from the group consisting of mental retardation, Down'ssyndrome, fragile X syndrome and autism a composition that includes atleast about 51 mole percent S-baclofen relative to the total S-baclofenand R-baclofen in the composition administered to the human.

In a further embodiment, the invention is a method of treating a human,comprising administering to a human having at least one conditionselected from the group consisting of mental retardation, Down'ssyndrome, fragile X syndrome and autism a composition that includes atleast about 51 mole percent R-baclofen relative to the total R-baclofenand S-baclofen in the composition administered to the human.

The subject treatment by the methods of the invention described hereincan be a rodent (e.g., mouse, rat) or a primate (e.g., a monkey, baboon,human). In a particular embodiment, the subject is a human.

In yet another embodiment, the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of fragile X syndromeand autism a composition that includes R-baclofen (e.g., at least about99 mole percent, about 95 mole percent, about 90 mole percent, about 85mole percent, about 80 mole percent, about 75 mole percent, about 70mole percent, about 65 mole percent, about 60 mole percent, about 55mole percent or about 51 mole percent R-baclofen relative to the totalR-baclofen and S-baclofen in the composition administered to the human).

In an additional embodiment, the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of fragile X syndromeand autism a composition that includes S-baclofen (e.g., at least about99 mole percent, about 95 mole percent, about 90 mole percent, about 85mole percent, about 80 mole percent, about 75 mole percent, about 70mole percent, about 65 mole percent, about 60 mole percent, about 55mole percent, or about 51 mole percent S-baclofen relative to the totalS-baclofen and R-baclofen in the composition administered to the human).

The compounds employed in the methods of the invention can beadministered to a subject with (e.g., before, concomitantly,sequentially or after) administration of other compounds that areemployed to treat a particular disorder or condition in the subject. Forexample, the compositions of the invention can be administered with atleast one member selected from the group consisting of a Group II mGluRagonist, Group II mGluR agonist, GSK3β antagonists, NAAG peptidaseinhibitors, Group I mGluR antagonist, an antidepressant, ananti-psychotic, an α2-adrenergic agonist, an anticonvulsant, a nicotinicreceptor agonist, an endocannabinoid receptor antagonist, a M1muscarinic receptor antagonist, and an AMPA agonist.

Glycogen synthase kinase-3 (GSK3) is an enzyme with a diverse number ofactions in intracellular signaling systems, regulating neuronalplasticity, gene expression and cell survival. GSK3β is known toparticipate in many signaling pathways and cellular activities. GSK3β isa key element of the signaling pathway whereby Group I mGluR signalingregulates dendritic synaptic protein synthesis.

N-Acetyl-1-aspartyl-1-glutamate (NAAG) is one of the three mostprevalent neurotransmitters in the mammalian brain. NAAG acts as anagonist at Group II metabotropic glutamate (e.g., mGluR2, mGluR3)receptors on neurons and glia. Specifically, NAAG activation of mGluRreceptors reduces cAMP and cGMP levels in neurons and astrocytes. Theneuropeptidases glutamate carboxypeptidase II and III (GCPII and III),also known as NAAG peptidases (hereafter “NPs”), are metalloproteasesthat hydrolyse NAAG to N-acetylaspartate (NAA) and glutamate followingthe release of NAAG into the synaptic cleft. They are found in limitedsites throughout the brain. Inhibition of GCPII and III increases NAAGlevels, with the consequent activation of presynaptic Group II mGluRsand inhibition of transmitter release, including release of GABA andglutamate.

A Group I mGluR antagonist (mGluR1 and mGluR5) can be administered tothe subjects with the compounds employed in the methods of theinvention.

mGluRs are a heterogeneous family of glutamate G-protein coupledreceptors. mGluRs are classified into three groups. Group I receptors(mGluR1 and mGluR5) can be coupled to stimulation of phospholipase C(PLC) resulting in phosphoinositide (PI) hydrolysis and elevation ofintracellular calcium levels, modulation of ion channels (e.g.,potassium channels, calcium channels, non-selective cation channels) andN-methyl-D-aspartate (NMDA) receptors. mGluR5 can be present on apostsynaptic neuron. mGluR1 can be present on a presynaptic neuronand/or a postsynaptic neuron.

Group II receptors (mGluR2 and mGluR3) and Group III receptors (mGluRs4, 6, 7, and 8) inhibit cAMP formation and G-protein-activated inwardrectifying potassium channels. Group II mGluRs and Group III mGluRs arenegatively coupled to adenylyl cyclase, generally present on presynapticneurons, but can be present on postsynaptic neurons and function aspresynaptic autoreceptors to reduce glutamate release from presynapticneurons. Activation of Group II mGluRs under very high neuron excitationcan dampen further release of neurotransmitters and stimulate therelease of neuroprotective growth factors, including trophic factors,from glia.

An antagonist (e.g., a Group I mGluR antagonist, a M1 muscarinicantagonist) is a substance that diminishes or abolishes the effect of aligand (e.g., glutamate, acetylcholine) that activates its receptor(e.g., mGluR1, mGluR5, M1 muscarinic receptor). The antagonist may actat the level of ligand-receptor interaction, such as by competitively ornon-competitively (e.g., allosterically) inhibiting ligand binding. Theantagonist (e.g., mGluR1 antagonist, mGluR5 antagonist, M1 muscarinicantagonist) can be, for example, a chemical antagonist or apharmacokinetic antagonist. The antagonist, for example, may actdownstream of the receptor, such as by inhibiting receptor interactionwith a G-protein or subsequent cell signaling events associated withG-protein activation, such as activation of PLC, an increase inintracellular calcium, the production of or levels of cAMP or adenylcyclase and stimulation or modulation of ion channels (e.g., potassiumchannels, calcium channels).

In one embodiment, the Group I mGluR antagonist is a mGluR5 antagonist.In another embodiment, the Group I mGluR antagonist is an mGluR1antagonist. Suitable Group I mGluR antagonists for use are described inU.S. Pat. Nos. 6,890,931 and 6,916,821, the teachings of both of whichare hereby incorporated by reference in their entirety. Suitable Group ImGluR antagonists can include, for example,(E)-6-methyl-2-styryl-pyridine (SIB 1893),6-methyl-2-phenylazo)-3-pyridinol, x-methyl-4-carboxyphenylglycine(MCPG) and 2-methyl-6-(phenylthynyl)-pyridine (MPEP).

Exemplary antagonists of mGluR5 for use in the methods of the inventionin combination with GABA agonists, in particular GABA(B) agonists (e.g.,baclofen), are described in WO 01/66113, WO 01/32632, WO 01/14390, WO01/08705, WO 01/05963, WO 01/02367, WO 01/02342, WO 01/02340, WO00/20001, WO 00/73283, WO 00/69816, WO 00/63166, WO 00/26199, WO00/26198, EP-A-0807621, WO 99/54280, WO 99/44639, WO 99/26927, WO99/08678, WO 99/02497, WO 98/45270, WO 98/34907, WO 97/48399, WO97/48400, WO 97/48409, WO 98/53812, WO 96/15100, WO 95/25110, WO98/06724, WO 96/15099 WO 97/05109, WO 97/05137, U.S. Pat. No. 6,218,385,U.S. Pat. No. 5,672,592, U.S. Pat. No. 5,795,877, U.S. Pat. No.5,863,536, U.S. Pat. No. 5,880,112, U.S. Pat. No. 5,902,817, all ofwhich are incorporated by reference in their entirety. Different classesof mGluR5 antagonists are described in WO 01/08705, WO 99/44639 and WO98/34907, the teachings of all of which are hereby incorporated byreference in their entirety.

The antipsychotic compound employed in the methods of the invention canbe a typical antipsychotic compound (also referred to as “a typicalantipsychotic agent” or a “typical antipsychotic drug”). In anotherembodiment, the antipsychotic compound is an atypical antipsychoticcompound (also referred to as an “atypical antipsychotic agent,” an“atypical antipsychotic drug” or a “second generation antipsychotic”).

Exemplary atypical antipsychotic compounds for use in the methods of theinvention can be at least one member selected from the group consistingof zuclopenthixol, amisulpride, aripiprazole(7-[4-[4-(2,3-dichlorophenyl)-1-piperazinyl]butoxy]-3-4-dihydrocarbostyril),nemonapride, abaperidone(7-[3-[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]propoxy]-3-(-hydroxymethyl)-4H-1-benzopyran-4-one,U.S. Pat. No. 5,736,588, the teachings of which are hereby incorporatedby reference in its entirety; belaperidone ((1.alpha., 5.alpha.,6.alpha.)-3-[2-[6-(4-fluorophenyl)-3-azabicyclo[−3.2.0]-hept-3-yl]ethyl]-2,4(1H,3H)quinazolinedione,U.S. Pat. No. 5,475,105, the teachings of which are hereby incorporatedby reference in its entirety; clozapine(8-chloro-11-(4-methyl-1-piperazinyl)-5H-dibenzo[b,e][1,4]diazepine,U.S. Pat. No. 3,539,573, the teachings of which are hereby incorporatedby reference in its entirety issued; iloperidone(1-[4-[3-[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]-3-methoxy-phenyl]ethanone;EP-402,644, the teachings of which are hereby incorporated by referencein its entirety; olanzapine(2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine;U.S. Pat. No. 5,229,382, the teachings of which are hereby incorporatedby reference in its entirety; perospirone(cis-2-[4-[4-(1,2-benzisothiazol-3-yl)-1-piperazinyl]butyl]-hexahydro-o-1H-isoindole-1,3(2H)-dione,U.S. Pat. No. 4,745,117, the teachings of which are hereby incorporatedby reference in its entirety; risperidone(3-[2-[4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidino]ethyl]-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-.alpha.]pyrimidin-4-one),U.S. Pat. No. 4,804,663, the teachings of which are hereby incorporatedby reference in its entirety; sertindole(1-[2-[4-[5-chloro-1-(4-fluorophenyl-1H-indol-3-yl]-1-piperidinyl]ethyl]imidazolidin-2-one),U.S. Pat. Nos. 4,710,500; 5,112,838; and 5,238,945, the teachings of allof which are hereby incorporated by reference in their entirety;tiospirone(8-[4-[4-(1,2-benzisothiazol-3-yl)-1-piperazinyl]butyl]-8-azaspiro[4-0.5]decane-7,9-dione),U.S. Pat. No. 4,411,901, the teachings of which are hereby incorporatedby reference in its entirety; ziprasidone(5-[2-[4-(1,2-benzoisothiazole-3-yl)-1-piperazinyl]ethyl]-6-chloro-1-,3-dihydro-2-one),U.S. Pat. No. 4,831,031, the teachings of which are hereby incorporatedby reference in its entirety; zotepine(2-[(8-chlorodibenzo[b,f]thiepin-10-yl)oxy]-N,N-dimethyl-ethanamine),U.S. Pat. No. 3,704,245, the teachings of which are hereby incorporatedby reference in its entirety; quetiapine(5-[2-(4-dibenzo[b,f][1,4]thiazepin-11-yl-1piperazinyl)ethoxy]ethano-1),U.S. Pat. No. 4,879,288, the teachings of which are hereby incorporatedby reference in its entirety; and blonanserin(2-(4-ethyl-1-piperazinyl)-4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydro-cycloocta[b]pyridine),U.S. Pat. No. 5,021,421, the teachings of which are hereby incorporatedby reference in its entirety; 2002/0123490, the teachings of which arehereby incorporated by reference in its entirety).

Antipsychotic agents, including atypical antipsychotic compounds for usein the invention can include, for example, Acetophenazine Maleate;Alentemol Hydrobromide; Alpertine; Azaperone; Batelapine Maleate;Benperidol; Benzindopyrine Hydrochloride; Brofoxine; Bromperidol;Butaclamol Hydrochloride; Butaperazine; Carphenazine Maleate;Carvotroline Hydrochloride; Chlorpromazine; Chlorprothixene; Cinperene;Cintriamide; Clomacran Phosphate; Clopenthixol; Clopimozide; ClopipazanMesylate; Cloroperone Hydrochloride; Clothiapine; Clothixamide Maleate;Clozapine; Cyclophenazine Hydrochloride; Droperidol; EtazolateHydrochloride; Fenimide; Flucindole; Flumezapine; FluphenazineDecanoate; Fluphenazine Enanthate; Fluphenazine Hydrochloride;Fluspiperone; Fluspirilene; Flutroline; Gevotroline Hydrochloride;Halopemide; Haloperidol; Iloperidone; Imidoline Hydrochloride;Lenperone; Loxapine; Mazapertine Succinate; Mesoridazine; Metiapine;Milenperone; Milipertine; Molindone Hydrochloride; NaranolHydrochloride; Neflumozide Hydrochloride; Ocaperidone; Olanzapine;Oxiperomide; Penfluridol; Pentiapine Maleate; Perphenazine; Pimozide;Pinoxepin Hydrochloride; Pipamperone; Piperacetazine; PipotiazinePalmnitate; Piquindone Hydrochloride; Prochlorperazine Edisylate;Prochlorperazine Maleate; Promazine Hydrochloride; Quetiapine;Remoxipride; Quetiapine Remoxipride Hydrochloride; Risperidone;Risperadone Rimcazole Hydrochloride; Seperidol Hydrochloride;Sertindole; Setoperone; Spiperone; Sulpiride; Thioridazine; Thiothixene;Thorazine; Tioperidone Hydrochloride; Tiospirone Hydrochloride;Trifluoperazine Hydrochloride; Trifluperidol; Triflupromazine;Ziprasidone Hydrochloride, analogs, derivative and combinations thereof(see, for example, U.S. Patent Application Nos: 20040019030 and2002/0123490, the teachings of both of which are hereby incorporated byreference in their entirety).

Antipsychotic compounds can have adverse side effects including, forexample, central nervous system depression, weight gain, sexualdysfunction, adverse effects on mood, anticholinergic side effects(cognitive impairment, reduced memory capacity, confusion, delirium, drymouth, blurred vision, worsening of glaucoma, constipation, urinaryretention, tachycardia), weight gain, diabetes mellitus, prolactinelevation, QTC prolongation, sedation, motor side effects such asextrapyramidal symptoms (EPS), dystonia, drug-induced parkinsonism,akathisia and potentially persistent drug-induced movement disorders andmotor side effects such as tardive dyskinesia (see, for example, U.S.Publication No: 2003/0008897, the teachings of which are herebyincorporated by reference in its entirety). These adverse side effectscan reduce patient compliance and lead to relapses.

Atypical antipsychotic compounds can reduce psychotic symptoms withfewer side effects (e.g., extrapyramidal side effects, rigidity, tremor,akathisia, cognitive impairment) than typical antipsychotics (see, forexample, Citrome, L., et al., Postgraduate Medicine 116: (2004)). Inaddition, atypical antipsychotics can also reduce aggression, repetitivebehaviors, hallucinations, delusions, a motivation and emotionalwithdrawal. However, not all side effects (e.g., weight gain, impairedglucose tolerance/lipid abnormalities, impaired social interaction) areeliminated by the use of atypical antipsychotics. Group I mGluRantagonist have been shown to reduce weight gain and decrease appetite.Combinations of Group I mGluR antagonists and antipsychotics in themethods of the invention described herein, in particular atypicalantipsychotics, may diminish or reduce the side effects of antipsychoticcompounds y reducing the dosage required and increase compliance tothereby treat subjects having conditions such as mental retardation,fragile X syndrome, Down's syndrome, autism, pervasive developmentaldisorders, including pervasive developmental disorders with no obvioussource.

The methods of the invention can further include the step ofadministering at least one member selected from the group consisting ofa nicotinic receptor agonist, an endocannabinoid receptor antagonist, anAMPA agonist, an antidepressant, an antipsychotic, an α2-adrenergicagonist, an anticonvulsant, a nicotinic receptor agonist, anendocannabinoid receptor antagonist and an AMPA agonist, which can beadministered before, during or after administration of the Group I mGluRantagonist, M1 muscarinic receptor antagonist and/or the GABA(B)receptor agonist, to the human.

In an embodiment, the GABA receptor agonist is administered (e.g.,before, concomitantly, sequentially or after) the M1 muscarinic receptoragonist.

In yet another embodiment, the invention method of treating a subject,comprising the step of administering to a subject having at least onecondition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes at least one M1 muscarinic antagonist (also referred to hereinas “M1 muscarinic receptor antagonist”).

The muscarinic acetylcholine (mACh) receptor family consists of fivemembers (M1, M2, M3, M4 and M5) and belongs to the G protein-coupledreceptor (GPCR) superfamily. A characteristic of GPCRs is that ligandbinding, the initial step in receptor signaling, elicits aconformational change in the receptor, leading to the activation of oneor more heterotrimeric G proteins. Mucarinic M1 receptors maypreferentially couple to the activation of PLC by pertussins toxin(PTx)-insensitive G proteins of the Gq family (Akam, E. C., et al.,British J. Pharmacology 132:950-958 (2001)).

Each muscarinic acetylcholine receptor shares common features includingspecificity of binding for the agonists acetylcholine andcarbamylcholine and the classical antagonists atropine and quinuclidinylbenzilate. Each receptor subtype couples to a second messenger systemthrough an intervening G-protein. M1, M3 and M5 receptors stimulatephosphoinositide metabolism whereas M2 and M4 receptors inhibitadenylate cyclase. The tissue distribution differs for each subtype. M1receptors are found in the forebrain, especially in the hippocampus andcerebral cortex. M2 receptors are found in the heart and brainstem whileM3 receptors are found in smooth muscle, exocrine glands and thecerebral cortex. M4 receptors are found in the neostriatum and M5receptor mRNA is found in the substantia nigra, suggesting that M5receptors may regulate dopamine release at terminals within thestriatum.

Activity of Gq-coupled, M1 muscarinic (also referred to herein as“muscarinic M1”) acetylcholine receptors can regulatehippocampal-dependent learning and memory consolidation. M1 muscarinicacetylcholine receptors (mAChRs), the primary Gq-coupled mAChRs inhippocampus, contribute to hippocampal-dependent memory.

M1 muscarinic antagonists, such as scopolamine and atropine, can abolishor diminish the action of signal transduction pathways that are mediatedby M1 muscarinic receptors. Scopolamine and atropine are alkaloids(natural, nitrogenous organic bases, usually containing tertiary amines)from the plant Atropa belladonna. The presence of an N-methyl group onatropine or scopolamine changes the activity of the ligand, possibly bypreventing a close interaction between the ligand and the membrane orlipophilic sites on the receptor. The methyl group may prevent thepenetration into the brain.

Exemplary M1 muscarinic receptor antagonists (also referred to herein as“M1 muscarinic antagonists” or muscarinic M1 antagonists”) for use inthe methods of the invention, in combination with a GABA agonist, inparticular, a GABA(B) agonist, can include the following:

Telenzepine is a racemic, analog that is more potent than Pirenzepine(Merck, Gastrozepen). Pirenzepine does not cross the blood brainbarrier, but telenzepine may and may have reactive metabolites. Themuscarinic M1 receptor antagonist (+/−)-telenzepine (about 3 mg orallyat about 6 p.m. for about 5 days) has been used to treat chronicobstructive pulmonary disease (COPD). The results indicate thatshort-term treatment with telenzepine does not improve airway functionin COPD patients, at least after administration by the oral route.

Trihexyphenidyl (Artane) is an antiparkinson agent of the antimuscarinicclass of agents and is chemically a tertiary amine. The drug isavailable as the hydrochloride salt.

Benztropine (Cogentin) (Merck) is an anticholinergenic and anantihistamine. It has been used in patients with schizophrenia to reducethe side effects of antipsychotic treatment, such as parkinsonism andakathisia. Benztropine is also a second-line drug for the treatment ofParkinson's disease. It improves tremor but not rigidity orbradykinesia. Benztropine is also sometimes used for the treatment ofdystonia, a rare disorder that causes abnormal muscle contraction,resulting in twisting postures of limbs, trunk, or face.

Dicyclomine (Bentyl) has been used to treat intestinal hypermotility,the symptoms of Irritable Bowel Syndrome (also known as spastic colon).It relieves muscle spasms in the gastrointestinal tract by blocking theactivity of a certain natural substance in the body. It is a smoothmuscle relaxer. Bentyl is also referred to as Byclomine, Dibent,Di-Spaz, Dilomine, Bentylol (Hoechst Marion Roussel), Formulex (ICN) andLomine (Riva).

Biperiden (1-(5-bicyclo[2.2.1]hept-2-enyl)-1-phenyl-3-(1-piperidyl)propan-1-ol) is an antiparkinsonian agent of the anticholinergic typeand is also referred to as Akineton® (BASF/Knoll Pharma).

Procyclidine (1-cyclohexyl-1-phenyl-3-pyrrolidin-1-yl-propan-1-olhydrochloride) has been used to treat schizophrenia to reduce the sideeffects of antipsychotic treatment, such as parkinsonism and akathisia.Procyclidine is also a second-line drug for the treatment of Parkinson'sdisease and can improve tremors, but not rigidity or bradykinesia.Procyclidine may be employed to treat dystonia (but not tardivedyskinesia), a rare disorder that causes abnormal muscle contraction,resulting in twisting postures of limbs, trunk, or face.

Scopolamine ((−)-(S)-3-Hydroxy-2-phenyl-propionic acid(1R,2R,4S,7S,9S)-9-methyl-3-oxa-9-aza-tricyclo[3.3.1.02,4]non-7-ylester) acts as a competitive antagonist at specific muscarinicacetylcholine receptors (the M1 receptor). Scopolamine is classified asan anticholinergic, or, more specifically, as an anti-muscarinic drug.

The quaternary muscarinic antagonist ipratropium and the long-lastingtiotropium can also be employed.

Enantomerically (+, −; R, S; d, l) enriched compositions (e.g., about 99mole percent, about 98 mole percent, about 95 mole percent, about 90mole percent, about 85 mole percent, about 80 mole percent, about 75mole percent, about 70 mole percent, about 65 mole percent, about 60mole percent, about 55 mole percent, about 51 mole percent of oneenantiomer in the composition relative to the total of both of theenantiomers in the composition) of the M1 muscarinic antagonists can beemployed in the methods described herein.

The methods of the invention can further include the step ofadministering a stimulant to the subject. “Stimulant,” as used herein,refers to any compound that promotes or increases wakefulness,alertness, physical activity, enhances cognition, enhances learning ordiminishes fatigue. Stimulants for use in the invention can includeamantadine, bupropion, atomoxetine, modafinil, caffeine,methylphenidate, nicotine, pseudoephedrine, and amphetamine, ormetabolites, isomers (e.g., d, 1, R, S) or derivatives thereof. Thestimulant used in the methods described herein can antagonize adenosinereceptor, inhibit dopamine reuptake, inhibit norepinephrine reuptake,antagonize H3 receptor, promote dopamine release, inhibit monoamineoxidase in the nervous system (the central nervous system, peripheralnervous system, and autonomic nervous system) or any combinationsthereof.

The compounds employed in the methods of the invention can beadministered to a subject with (e.g., before, concomitantly,sequentially or after) administration of other compounds that areemployed to treat a particular disorder or condition in the subject. Forexample, the compositions of the invention can be administered with atleast one member selected from the group consisting of anantidepressant, a Group I mGluR antagonist, a muscarinic M1 antagonist,an anti-psychotic, an α2-adrenergic agonist and an anticonvulsant.

The identification of appropriate compounds, such as antidepressants,antipsychotics, α2-adrenergic agonists, anticonvulsants, a nicotinicreceptor agonist, an endocannabinoid receptor antagonist and AMPAagonists, for use in the methods of the invention would be known to oneskilled in the art (see, for example, Beryy-Kravis, E., et al., MentalRetardation and Developmental Disabilities 10: 42-48 (2004), theteachings of which are hereby incorporated by reference in itsentirety).

The compounds employed in the methods of the invention can beadministered to the subject acutely (briefly or short-term) orchronically (prolonged or long-term). For example, subjects can beadministered the compounds for days (1-7), months (1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12), years (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) or forlife.

Subjects treated by the methods of the invention can have at least onecondition selected from the group consisting of a sensory hyperarousaldisorder, an anxiety disorder, a seizure disorder, a gastrointestinaldisorder, a sleep disorder, aggressive or aberrant behavior and animpaired cognitive function.

Subjects treated by the methods of the invention can also have at leastone condition selected from the group consisting of a social interactionabnormality, limited interests and repertoire of behaviors and a socialavoidance condition.

Subjects (e.g., humans, also referred to herein as “patients”) treatedby the methods of the invention can have a cognitive impairment, such asan impairment in reaction time, eye tracking, motor coordination, gait,oral-motor function, communication, learning, attention, executivefunction, reaction time, learning, information processing,conceptualization, problem solving, verbal fluency or memory (e.g.,memory consolidation, short-term memory, working memory, long-termmemory, declarative memory or procedural memory).

Impairment in a cognitive function treated by the methods describedherein can be an impairment in attention, which is the capacity orprocess of selecting out of the totality of available sensory oraffective stimuli, those stimuli that are most appropriate or desirablefor focus at a given time (Kinchla, R. A., et al., Annu. Rev. Psychol.43:711-742 (1992)). The impairment in a cognitive process can be animpairment in executive function, which are neuropyschological functionssuch as decision making, planning, initiative, assigning priority,sequencing, motor control, emotional regulation, inhibition, problemsolving, planning, impulse control, establishing goals, monitoringresults of action and self-correcting (Elliott, R., Br. Med. Bull.65:49-59 (2003)). The cognitive impairment can be an impairment inalertness, wakefulness, arousal, vigilance, and reaction timeinformation processing, conceptualization, problem solving and/or verbalfluency. One of skill in the art would be capable of identifying andevaluating the impairment in a cognitive function in the individual.

An “effective amount,” also referred to herein as a “therapeuticallyeffective amount,” when referring to the amount of a compound orcomposition (e.g., baclofen, a M1 muscarinic receptor antagonist) isdefined as that amount, or dose, of a compound or composition that, whenadministered to a subject, is sufficient for therapeutic efficacy (e.g.,an amount sufficient decrease to exhibit a clinical improvement in abehavior or mental cognitive test score; alleviate sensory hyperarousaldisorder, an anxiety disorder, a seizure disorder, a gastrointestinaldisorder, a sleep disorder, prevent weight gain, decrease obsessivecompulsive tendencies and manners).

The methods of the present invention can be accomplished by theadministration of the compounds of the invention (e.g., compositionsincluding baclofen) by enteral or parenteral means. The route ofadministration can be by oral ingestion (e.g., tablet, capsule form) orintramuscular injection of the compound. Other routes of administrationcan include intravenous, intraarterial, intraperitoneal, or subcutaneousroutes, nasal administration, suppositories and transdermal patches.

In an embodiment, the compounds (e.g., baclofen, Group I mGluRantagonists, M1 muscarinic receptor antagonists) employed in the methodsof the invention can be administered in a dose of between about 0.01mg/kg to about 0.1 mg/kg; about 0.001 mg/kg to about 0.01 mg/kg; about0.001 to about 0.05 mg/kg; about 0.1 mg/kg to about 1 mg/kg body weight;about 1 mg/kg to about 5 mg/kg body weight; or between about 5 mg/kg toabout 15 mg/kg body weight.

The compounds can be administered in doses of about 0.1 mg, about 1 mg,about 2 mg, about 2.5 mg, about 5 mg, about 10 mg, about 15 mg, about 20mg, about 25 mg, about 30 mg, about 40 mg, about 45 mg, about 50 mg,about 60 mg, about 80 mg, 100 mg, about 200 mg, about 250 mg, about 300mg, about 350 mg, about 400 mg, about 500 mg, about 600 mg, about 700mg, about 900 mg, about 1000 mg, about 1200 mg, about 1400 mg, about1600 mg or about 2000 mg, or any combination thereof. The compounds canbe administered once a day or multiple (e.g., two, three, four, five)times per day.

In yet another embodiment, the subject is administered the compoundsemployed in the methods of the invention at about 1 mg BID (twice aday), about 2 mg BID, about 3 mg BID, about 5 mg BID, about 10 mg BIDand about 10 mg TID (three times a day).

In another embodiment, the compounds employed in the methods of theinvention can be administered at a dosing regimen that includesprogressive or escalating increases in the compound over time oftreatment. For example, a subject can be treated with baclofen (e.g.,R-baclofen, such as between about 20 to about 40 mg per day) at a doseof about 2 mg/day at days 1, 2, 3 of treatment; about 4 mg/day at days4, 5, 6 of treatment; about 6 mg/day at days 7, 8, 9 of treatment; about20 mg/day at days 13, 14, 15 of treatment and about 30 mg/day at days16, 17 and 18 of treatment.

The compounds of the invention can be administered to the human in aselected dose (e.g., about 10 mg dose taken 3 times a day or about 15 mgdose given as three doses each of which is about 5 mg) while monitoringimprovements in the human (e.g., cognition, behavior). If the human doesnot exhibit any improvement, the compositions employed in the methodscan be increased, decreased or stopped until a beneficial effect isobserved. For example, if treatment began with three (3) doses of about10 mg daily and the human subsequently exhibited no apparentimprovement, the dose could be increased to three (3) doses of about 15mg a day, decreased to two (2) doses of about 10 mg a day or treatmentcould be halted for a single dose, a number of days or weeks andsubsequently commenced following the “mini-drug holiday.”

“Mini-drug holiday,” as used herein, refers to removal of the human fromtreatment or a decrease in the dose of the compound, followed byre-introduction of the treatment, at a dose equivalent to, below or inexcess of the dose the human received prior to the mini-drug holiday.

In yet another embodiment, the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes baclofen, wherein the baclofen is administered to the human ata dose of about 2 mg per day for days 1, 2 and 3 of treatment, a dose ofabout 4 mg per day for days 4, 5 and 6 of treatment, a dose of about 6mg per day for days 7, 8 and 9 of treatment, a dose of about 10 mg perday for days 10, 11 and 12 of treatment, a dose of about 20 mg per dayfor days 13, 14 and 15 of treatment, a dose of about 30 mg per day fordays 16, 17 and 18 of treatment and a dose between about 15 mg to about80 mg per day for the duration of the treatment or between about 30 mgto about 80 mg per day for the duration of the treatment.

In an additional embodiment, the invention is a method of treating ahuman, comprising the step of administering to a human having at leastone condition selected from the group consisting of mental retardation,Down's syndrome, fragile X syndrome and autism a composition thatincludes baclofen, wherein the baclofen is administered to the human ata dosing regimen of at least one member selected from the groupconsisting of about 1 mg twice a day, about 2 mg twice a day, about 3 mgtwice a day, about 5 mg twice a day, about 10 mg twice a day and about10 mg three times a day.

One skilled in the art can adjust doses of compounds for use in themethods. A suitable dose of a compound (e.g., a GABA(B) agonist, such asbaclofen; M1 muscarinic receptor antagonist) for use in a subject can bea titrated dose. For example, the subject would initially receive a lowdose, doses would be increased if the low dose was not effective. Dosescould be increased about every 3-7 days of treatment, with adjustmentsas necessary based on side-effects. The doses can be titrated until themaximal tolerated dose or maximally effective dose is determined.Subjects can be maintained at the maximally effective or maximallytolerated dose.

In one embodiment, the baclofen administered to the human is a racemicmixture (50 mole percent R-baclofen and 50 mole percent S-baclofen). Inanother embodiment, the baclofen administered to the human is enrichedfor one enantiomer of baclofen.

The enatiomerically enriched baclofen can include a composition that isat least about 51 mole percent, at least about 55 mole percent, at leastabout 60 mole percent, at least about 65 mole percent, at least about 70mole percent, at least about 75 mole percent, at least about 80 molepercent, at least about 85 mole percent, at least about 90 mole percent,at least about 95 mole percent, at least about 98 mole percent, at leastabout 99 mole percent or 100 mole percent R-baclofen relative to thetotal R-baclofen and S-baclofen in the composition administered to thehuman.

Alternatively, the enatiomerically enriched baclofen can include acomposition that is at least about 51 mole percent, at least about 55mole percent, at least about 60 mole percent, at least about 65 molepercent, at least about 70 mole percent, at least about 75 mole percent,at least about 80 mole percent, at least about 85 mole percent, at leastabout 90 mole percent, at least about 95 mole percent, at least about 98mole percent, at least about 99 mole percent or 100 mole percentS-baclofen relative to the total S-baclofen and R-baclofen in thecomposition administered to the human.

The compounds employed in the methods of the invention can beadministered alone or can be coadministered to the patient.Coadministration is meant to include simultaneous or sequentialadministration of one or more of the compounds (e.g., baclofen and a M1muscarinic receptor antagonist) employed in the methods of the inventionindividually or in combination. The mode of administration can beconducted sufficiently close in time to each other so that the effectson the subject are maximal. It is also envisioned that multiple routesof administration (e.g., intramuscular, oral, intranasal, inhalation,topical, transdermal) can be used to administer the compounds employedin the methods of the invention.

The compounds employed in the methods of the invention can beadministered alone or as admixtures with conventional excipients, forexample, pharmaceutically, or physiologically, acceptable organic, orinorganic carrier substances suitable for enteral or parenteralapplication which do not deleteriously react with the compound(s)administered to the subject. Suitable pharmaceutically acceptablecarriers include water, salt solutions (such as Ringer's solution),alcohols, oils, gelatins and carbohydrates such as lactose, amylose orstarch, fatty acid esters, hydroxymethycellulose, and polyvinylpyrrolidine. Such preparations can be sterilized and, if desired, mixedwith auxillary agents such as lubricants, preservatives, stabilizers,wetting agents, emulsifiers, salts for influencing osmotic pressure,buffers, coloring, and/or aromatic substances and the like which do notdeleteriously react with the compounds employed in the methods of theinvention. The preparations can also be combined, when desired, withother active substances to reduce metabolic degradation. A preferredmethod of administration of the compounds employed in the methods of theinvention can be oral administration, such as a tablet.

The compounds employed in the methods of the invention, alone, or whencombined with an admixture, can be administered in a single or in morethan one dose over a period of time to confer the desired effect (e.g.,alleviate symptoms of autism, improve sleep patterns, decrease sensoryhyperarousal disorder, alleviate an anxiety disorder, a seizuredisorder, a gastrointestinal disorder, an impaired cognitive function,weight gain).

When parenteral application is needed or desired, particularly suitableadmixtures for the compounds employed in the methods of the inventionare injectable, sterile solutions, preferably oily or aqueous solutions,as well as suspensions, emulsions, or implants, including suppositories.In particular, carriers for parenteral administration include aqueoussolutions of dextrose, saline, pure water, ethanol, glycerol, propyleneglycol, peanut oil, sesame oil, polyoxyethylene-block polymers, and thelike. Ampules are convenient unit dosages. The compounds for use in themethods of the invention can also be incorporated into liposomes oradministered by transdermal pumps or patches. Pharmaceutical admixturessuitable for use in the present invention are well-known to those ofskill in the art and are described, for example, in PharmaceuticalSciences (17th Ed., Mack Pub. Co., Easton, Pa.) and WO 96/05309 theteachings of which are hereby incorporated by reference.

The dosage and frequency (single or multiple doses) administered to anindividual can vary depending upon a variety of factors, including theduration of condition of the subject (e.g., sensory hyperarousaldisorder, anxiety disorder, seizure disorder, gastrointestinal disorder,sleep disorder, an impaired cognitive function, weight gain, obsessivecompulsive behaviors); the route of administration of the compound;size, age, sex, health, body weight, body mass index, and diet of therecipient; nature and extent of symptoms of the disorder being treated(e.g., sensory hyperarousal disorder, anxiety disorder, seizuredisorder, gastrointestinal disorder, sleep disorder, impaired cognitivefunction), kind of concurrent treatment (e.g., behavioral modification,anti-depressant medications, α2-adrenergic agonists, anticonvulsants, anicotinic receptor agonist, an endocannabinoid receptor antagonist, AMPAagonists, anti-psychotics), complications from, for example, a sensoryhyperarousal disorder, anxiety disorder, seizure disorder,gastrointestinal disorder, sleep disorder or impaired cognitivefunction; or other health-related problems. Other therapeutic regimensor agents can be used in conjunction with the methods of the presentinvention. For example, the administration of the compounds employed inthe methods of the invention can be accompanied by behavioralmodifications, anti-depressant medications and anti-psychoticmedications. Adjustment and manipulation of established dosages (e.g.,frequency and duration) are well within the ability of those skilled inthe art.

An additional embodiment of the invention is the use of the compositionsand compounds (e.g., baclofen, M1 muscarinic receptor agonist, Group ImGluR antagonists) for the manufacture of a medicament to treat subjects(e.g., humans) having the conditions described herein (e.g., fragile Xsyndrome, autism).

A further embodiment of the invention is a pharmaceutical compositionthat includes the compositions and compounds described herein (e.g.,baclofen, M1 muscarinic receptor antagonists, Group I mGluR antagonists)to treat subjects having the conditions described herein (e.g., fragileX syndrome, autism).

A description of example embodiments of the invention follows.

The teachings of all patents, published applications and referencescited herein are incorporated by reference in their entirety.

EXEMPLIFICATION Example 1 Treatment of Autism with Baclofen

A 23 year old female with autism spectrum disorder (height 61″, weight170 lbs) was hospitalized and being preparing for port-a-catheterplacement to begin TPN for an undetermined period of time to allow totalgut rest. Baclofen was prescribed 5 mg tid (three times daily) toimprove bowel motility. Within about 24 hours abdominal pain appeared tobe resolved and GI motility became functional, allowing oral feeding.Over the next several days and weeks improvements were noted incognitive and behavioral domains that had been unchanged for over 10years.

For example, improvements with social interaction as evidenced by

a. Increased interest and response to spoken language

b. Increased spontaneous attempts to interact

c. Increased joint attention and eye contact;

improvements in motor coordination as evidenced by

a. greatly improved oral motor b improved motor planning

c. improved gait;

improvements in communication as evidenced by a immediate andappropriate responses to spoken language (receptive language)

b. increase in verbal language (“No” “OK” “go”) and attempts at wordapproximations

c. increased spontaneous use of augmentative communication device;

dramatic improvements in mood and affect “looks comfortable, calm andhappy”;

increased interest and motivation to work on cognitive/educationalactivities;

greatly increased physical stamina and energy;

increased repertoire of age appropriate behavior and interests.

After about 3 weeks of baclofen (about 5 mg tid), the beneficial effectsbegan to wane. At that time the dose was increased to about 10 mg tid,but the increase in dose did not produce the beneficial effects notedabove. A single dose of about 15 mg produced the typical side effects ofsedation. An alternative dosing regimen included omission of the eveningdose for one day (e.g., a mini-drug holiday) followed by resumption ofthe original dose (about 5 mg tid) the next day, which resulted inbeneficial effects on cognitive and behavioral domains, as describedabove. Efficacy has been observed for over about 11 weeks at present ata dose of about 10 mg bid (twice a day). When positive effects begin towane, a single dose is omitted and full efficacy is again observed.During the first two months it was necessary to skip a dose about onceevery 5-7 days to maintain full efficacy, more recently this intervalhas increased to once every 10-14 days.

The improvements observed were in domains that had been unchanged andstable for over ten years (e.g., communication, verbalization, jointattention, socialization, coordination), maximal benefits occurred atdoses lower than those typically found effective for treatinggastrointestinal spasticity (the approved indication), improvements werecorrelated with a specific dose range, and tolerance to beneficialeffects was not rescued by increasing the dose but was repeatedlyrescued by skipping a single dose.

This 23 year old female was on the following medications at the time ofinitiation of baclofen:

-   -   175 mg topamax: pain and history of 4 gran mal seizures (none        since 2002);    -   30 mg prevacid bid;    -   150 mg zantac tid;    -   8 mg zofran every 8 hours to treat chronic vomiting;    -   500 mg Philips magnesium tid to treat constipation;    -   dulcolax as needed for constipation;    -   100 mg tramadol as needed (every 6-8 hours); and    -   oxycodone for breakthrough pain

This 23 year old female was given a trial of amitryptiline for 3 days inthe hospital prior to baclofen treatment with no effect. The tramadoland oxycodone were discontinued when the baclofen was started. Over thepast few weeks she was weaned off many of the above medications. Hercurrent medications are:

-   -   baclofen 20 mg (10 mg twice a day);    -   topamax 125 mg; and    -   zantac 150 mg.

Example 2 Treatment of Autism with Baclofen

A 12 year old male with autism spectrum disorder (height=54″, weight=64lbs) was treated with baclofen. Baclofen (about 5 mg bid) was initiallyadministered with baclofen in an attempt to reduce gastroesophagealreflux symptoms. Over the next several days and weeks improvements werenoted in several cognitive and behavioral domains such as increasedinterest and response to spoken language and attempts to communicateverbally. Dramatic improvements in mood and affect such as “lookscomfortable, calm and happy” were also noted. Increased alertness,interest and motivation to work on cognitive/educational activities withschool instructors were also noted. School personnel record behavior ona daily basis, are not informed regarding changes in drug treatment anddid not know that baclofen had been prescribed for this subject. Dailyscores were averaged over the five weeks after initiating baclofentherapy and compared to the average scores for the five weeksimmediately preceding initiation of baclofen therapy. Significantimprovements following initiation of baclofen were noted in thefollowing domains:

-   -   Episodes of scratching, hitting and kicking others decreased        from an average of 17+2 (mean±SE) to 6+1 episodes a day episodes        a day.    -   Episodes of hand biting or hitting of the head decreased to from        an average of 15+2 to 6+1 episodes a day.    -   Episodes of eye diversion decreased from an average of 10+2 to        5+2 episodes a day.

These benefits have been maintained for 5 weeks on stable dosing at 5 mgbid.

Concommitant medications at the time of initiation of baclofen:

-   -   Tegretol 800 mg/day for history of 4 gran mal seizures    -   Prevacid 30 mg bid    -   Lamotrigine 25 mg/day    -   Singulair 5 mg/day    -   Carafate 1 gm bid

Example 3 Treatment of Autism with Baclofen

A 9 year old male with autism spectrum disorder (height=46″, weight=47lbs) was treated with baclofen. Baclofen (5 mg bid) was initiated in anattempt to reduce gastroesophageal reflux symptoms. Over the nextseveral days and weeks improvements were noted in cognitive andbehavioral domains, such as increased interest and response to spokenlanguage and spontaneous attempts to communicate. Parents also noted animprovement in sleep patterns, mood and affect. Increased alertness,interest and motivation to work on cognitive/educational activities werenoted by school personnel. School personnel record behavior on a dailybasis, are not informed regarding changes in drug treatment and did notknow that baclofen had been prescribed for this subject. Daily scoreswere averaged over the five weeks after initiating baclofen therapy andcompared to the average scores for the five weeks immediately precedinginitiation of baclofen therapy. Improvements were noted in the frequencyof startle/tremor activity, which is thought to reflect brief(approximately 2 second duration) seizure activity in this subject.After initiation of baclofen treatment, episodes of startle tremordecreased from an average of 66+24 (mean±SE) to 16+5 episodes a day.Similarly, the incidence of spontaneous attempts to communicateincreased from an average of 11+1 to 21+2 episodes a day.

These benefits have been maintained for 5 weeks on stable dosing at 5 mgbid.

Concommitant medications at the time of initiation of baclofen:

-   -   Tegretol 800 mg/day for history of seizures    -   Prevacid 30 mg bid    -   Lamotrigine 50 mg/day    -   Singulair 10 mg/day

Example 4 Autism Spectrum Disorder with Baclofen

Racemic baclofen was administered to treat twenty one (21) subjects (12males and 9 females) with autism spectrum disorder (see Table 1). Thesubjects had serious behavioral problems that were not controlled with avariety of medications including antiepileptics (N=14), antipsychotics(N=8) and antidepressants (N=6). Doses of baclofen administered to thesubjects were titrated on a weekly basis from about 2.5 mg twice a day(BID) to a maximum of about 15 mg three times a day (TID), with amaximum duration of treatment of about 8.5 months.

The clinician rated overall impression of improvement with baclofentreatment on a seven category scale ranging from “much worse,” “worse,”“slightly worse,” “no change,” “slightly better,” “better” or “muchbetter.” Subjects undergoing baclofen treatment were considered to haveimproved if the clinician rating was either “much better” or “better.”Likewise, baclofen was considered to not improve the condition of thesubject if the clinician rating was “slightly worse,” “no change” or“slightly better.” If a subject was worse on baclofen treatment, theclinician rating would be “worse” or “much worse.”

Eight (8) of the 21 subjects demonstrated improvement in presentingsymptoms including less irritability/aggression, better communication orimproved social interaction. Other areas of improvement includedincreased class participation and decreased hyperactivity. Eleven (11)subjects did not improve and two (2) subjects worsened. Eight (8)subjects did not continue on baclofen treatment. These included 2 whodid not improve, 1 patient who improved but did not continue treatment,3 patients who stopped for unrelated reasons, and 2 who had adverse sideeffects that were considered related to initiation of baclofen treatment(drowsiness in one and hyperactivity in the other). Other adverseeffects included difficulty sleeping, otitis, increased gastrointestinaldiscomfort/loose stools and increase in finger stims.

Racemic baclofen has been used to treat spasticity and has awell-defined safety profile in adults and children. There is norationale for prescribing baclofen to children with disorders of braindevelopment. In the patients with fragile X syndrome, doses of racemicbaclofen were titrated from a starting dose of about 2.5 or about 5 mgBID to a maximum of about 20 mg TID, with a maximum duration of 4months. Two of five patients demonstrated improvement in behavior,including less irritability, aggression and agitation, two are stillundergoing titration, and treatment was discontinued in one subject whodeveloped sleepiness and irritability when the dose was increased toabout 20 mg/day. Other areas of improvement included increased classparticipation and decreased hyperactivity. Of note, all fragile Xsyndrome patients (Example 5) were receiving psychoactive drugs and fourof five were receiving concurrent treatment with atypicalantipsychotics. In the patients with idiopathic autism, doses weretitrated from about 2.5, 5 or 10 mg BID to a maximum of about 15 mg TID,with a maximum duration of about 8.5 months. Eight of the 21 patientsdemonstrated improvement in presenting symptoms, including lessirritability/aggression, better communication/social interaction, anddecreased frequency and severity of gastrointestinal symptoms. Otherareas of improvement included increased class participation anddecreased hyperactivity. Baclofen treatment was discontinued in eightpatients including one who improved, five who did not improve and twopatients who worsened (increased hyperactivity in both). Of note, thesepatients were commonly receiving concurrent treatment with psychoactivedrugs including antiepileptics (N=14), antipsychotics (N=8) andantidepressants (N=6). The overall impression was that baclofen wasparticularly useful for treatment of irritable and aggressive behavior.

TABLE 1 Baclofen Treatment in Autism Spectrum Disorder Patients MaximumReason for Total Daily Age Weight Concomitant Concomitant Baclofen Dose(Yrs) (kg) Sex Conditions Medications Treatment (mg) 14 — F NoneRisperdal, agitation 20 fluoxitine, valproic acid 29 — M Nonefluoxetine, compulsions 40 Abilify, Remeron 37 — F Bipolar moodRisperdal, agitation, 20 disorder Synthroid, dystonia Temazepam,baclofen, benztropine 15 59.1 F Mental retardation Trileptol,aggression, 45 Seroquel, rigidity, Lexapro insistence on sameness 14 50F Mental retardation Lithobid, aggression, 20 Lithium irritability,carbonate, constant Seroquel movement 4 22 M Lactose Vitamingastrointestinal 5 intolerance, chronic cocktail, dysfunction, diarrhea,suspected Pepcid, Vit. behavioral metabolic problem, B6, A, D, symptomsincreased Nystatin, Zinc, illness/fevers in Colostrum winter (symptomsGold of autism decreased during these periods), history of regression 20mos. 13 65.2 M GI tract issues, Vitamin restrictive, 10 undefinedcocktail (CO repetitive metabolic issues, QID, B1, B2, behaviors,processing E) decreased problems-needs energy level augmentativecommunication device for language 12 50.1 F Seizures, reflux, Paxil, GIdistress, 5 unspecified Donovex behavioral metabolic disorder, ointment,symptoms psoriasis, anxiety, omeprazole, PICA, weight loss, Atarax,dysphagia Depakote 9 50.7 M esophagitis, allergy, Singulair, GI tract 20questionable Prevacid, issues, sleep metabolic disorder, Camitine,problems, distractibility, rash, Vitamin behavior sleep problems,cocktail (CO, gluten and casein- Q10, E, C, B1, free diet B2) 7 29.1 Mreflux, sour Lexapro, GI and 20 stomach, no Prevacid, behavioralappetite, suspected Vitamin issues metabolic disorder, cocktail (CO,attention problems, Q10, E, C, B1, anxiety, depression, B2) chronic skineruptions on face 32 81.2 M seizures, Depakote, GI tract 20 esophagitis,reflux, propranolol, issues, reflux constipation, omeprazole,hypertyroidism, Singulair, anxiety, bursitis, Keppra, agitation,Risperdal, aggression, Synthroid tiredness/low energy level 9 33 Mstomach pains, Vitamin B, C, GI concerns, 15 GERD, increased omega fattyanxiety, acylcarnitine, acids, impulsivity auditory sensitivity,Prevacid, anxiety, recurrent Creon mouth sores, allergic to eggs and soy6 25 M Landau-Kleffner Periactin, Significant 10 Syndrome, grade 2Depakote, abdominal esophagitis, Prevacid, pain, crying abdominal pain,Singulair, confirmed Bentyl, metabolic Donnatal, diagnosis, possibleVitamin migraines, crying cocktail, episodes, carafate, Milk regressionsin HX of Magnesia 15 45.5 M anxiety Kondremal, severe 20 Pentasa,abdominal Thazadose, distress, Tenex constipation 21 65 F Weeklyseizures, Depakote, severe GI 10 severe abdominal Lamictal, issuedistention/constipation, levothyroxine, hypothyroid, Prevacidrespiratory distress 9 25 M Seizures, GERD, Singulair, GI disorders 10abdominal pain, Miralax, constipation, Prevacid, esophagitis, rectumLamictal, stromal Tegretol, fibrosis/reactive Diastat hyperplasiaaccudial, suggestive of Vitamin mucosal prolapse, cocktail,mitochondrial Pentasa dysfunction, eczema 14 33.2 M Seizures, ulcers,Vitamin GI tract 10 gastritis, cocktail, issues, esophagitis, Carafate,lethargy diarrhea, Lamictal, constipation, Tegretol, GERD, GI nodularPrevacid, lymphoid Singulair, hyperplasia, Carnitine presumedmitochondrial disorder 19 93 M increased CPK, Carnitine, behavioral 10anxiety, +PPD, −CXR Celexa, symptoms, Zyrtec, constipation, Nicomide,GERD Risperdal, Adderall 8 26.4 F Daily seizures, Prevacid, GI tract 20reflux, abdominal Pepcid, issues, pain, orthopedic Carafate,irritability disabilities (wheel Depakote, chair confined) Lamictal,Miralax, Camitor, Keppra 11 35.2 F non-specific colitis, Dipentum, GI 10irritable bowel, Ultrase MT disorder/GU reflux, overgrowth 12, Peptodisorder, syndrome, GI Bismol, Carb- behavior motility issues, Digest,metabolic/mitochondrial Sporanox, disorder, Vitamin C, potentialpernicious Magnesium, puberty, irritable Ditropan, bladder, minimalMiralax, bilateral Flagyl, Cardex pelviectasis, sleep disturbance,oromotor apraxia, small pituitary Treatment Adverse Age Duration OverallAreas of Events/ (Yrs) (months) Ongoing Improvement¹ ImprovementDiscontinuation 14 7.5 Y Not Improved calmer after None first few weeks29 4 Y Not Improved repetitive/self- None stimulatory behaviors 37 1 NNot Improved slightly calmer hospitalized with sepsis from a UTI relatedto poor communication and side effects of risperidone (which pre-existed baclofen)/ baclofen discontinued 15 3.5 Y Improved calmer, Nonebrighter, decreased aggression, more compliant, decreased screaming 145.5 Y Improved calmer, None happier appearance, decreased irritability,dramatic decrease in aggression (10 BID)  4 1 N Not Improved calm atfirst; increased loose zone out week stools/ 2-3, D/C by not improvedweek 5 (questionable dosing during vacation) 13 4.5 N Improvedeasygoing, None/ able to tolerate Discontinued stress/transitions,baclofen to see behavior, if changes were more signing, directly relatedable to sleep to baclofen (may more/consistently, re-start) GI functionmore comfortable 12 >1 N Not Improved None None/ No change  9 1 YImproved Happier, “went back to improved old self” on articulation,higher dose (10 initiates BID) interactions, stomach better, increase insounds (language)  7 7 Y Not Improved Improved None mood, toleratescrowds, calmer, more social and interactive, sleeping through night, nosour stomach, decreased anxiety 32 3 Y Not Improved pleasant, Noneincrease in obsessions, especially music making, better transition,increase in hand tremors, wants to be social, requires naps/sleepingbetter, increase in brief seizures (has history), ability to retrievelanguage/use more words  9 1 Y Not Improved improved takes longer tomood, less fall asleep, aggressive, slight increase in language fingerstims improvement, improved BMs, more focused on environment, calmer  63 N Not Improved elated/no pain, otitis (a week calmer, more afterstarting interactive (all baclofen)/ during first major week); allmanagement symptoms issues with other returned medication despite dosageadjustments 15 1 N Worsened More engaged, increased positive sleephyperactivity; change, BMs; increased GI all during 1st discomfort andweek only, crying after 1st then returned week to baseline 21 <1 N NotImproved None more drowsy (discontinued)  9 8.5 Y Improved happier/moreNone comfortable, behavior better, more alert, more social/interactiveimproved sleep, decreased seizures, decreased constipation, better ableto stay on task 14 8.5 Y Improved happier, hyperactivity calmer, more(but “happy”), focused, better sleeping at control over school body,more aware of surroundings, decrease in self-injurious behaviors with GIflare-ups, decreased seizures, decreased frequency/severity of GIissues, improved toileting 19 7 Y Improved more even, not Noneaggressive, less rocking, more appropriate socially, constipation nolonger an issue, more pleasant  8 <1 N Worsened None increasedhyperactivity (discontinued) 11 5.5 Y Not Improved mood/affect, Nonebehavior, repetitive behaviors, social interaction, sleep, GI function(hard to rule out other variables), better bladder control ¹Clinician'soverall impression of improvement with baclofen: Improved includes “muchbetter” and “better”; Not Improved includes “”slightly better” and “nochange”; Worsened includes “worse” and “much worse”

Example 5 Fragile X Syndrome

Racemic baclofen was administered to treat five (5) male subjects withfragile X syndrome (Table 2). These subjects had serious behavioralproblems that were incompletely controlled with typical psychoactivemedications. Baclofen was added to concomitant antipsychotic treatmentin four (4) of the five (5) subjects. Doses were titrated from about 2.5mg BID to a maximum of about 20 mg TID, with a maximum duration of about4 months. Clinicians rated their overall impression of improvement withbaclofen treatment on a seven category scale ranging from “much worse,”“worse,” “slightly worse,” “no change,” “slightly better,” “better” or“much better”. Subjects were considered “Improved” if the clinicianrating was either “much better” or “better”; considered “Not Improved”if the rating was “slightly worse”, “no change” or “slightly better”;and considered “Worsened” if rated “worse” or “much worse”. Two of the 5patients demonstrated an improvement in behavior, including lessirritability, aggression and agitation. Other areas of improvementincluded increased class participation and decreased hyperactivity. Twosubjects did not demonstrate obvious improvement and the dosing regimenis still being adjusted. One subject worsened as evidenced by excessivesleepiness, increased irritability, screaming and swearing and baclofenwas discontinued.

TABLE 2 Baclofen Treatment in Fragile X Patients Maximum Total DailyTreatment Age Weight Concomitant Reason for Baclofen Dose DurationOverall Areas of (Yrs) (kg) Medications Treatment (mg) (months) OngoingImprovement¹ Improvement 6 27 Abilify, Agitation, head-banging, 10 4 YImproved Decreases in all Risperdal fecal smearing aberrant behaviors;increased class participation 17 68 Zoloft Severe aggression, self- 203.5 Y Improved Decreased abusive behavior, biting irritability andhyperactivity; fewer outbursts 20 96 Abilify, Celexa, Aggression,yelling, 20 1 N Worsened None Xanax, lithium cursing 21 76 Abilify,Cogentin Agitation, anxiety, 60 3 Y Not Improved Decreases in vomitingbehaviors for 1^(st) week of treatment 26 61 Abilify, TrileptalAggression, agitation 30 2 Y Not Improved Decreased outbursts for 3-4weeks ¹Clinician's overall impression of improvement with baclofen:Improved includes “much better” and “better”; Not Improved includes“”slightly better” and “no change”; Worsened includes “worse” and “muchworse”

Example 6 Treatment of Fragile X Knockout Mice with a GABA(B) AgonistRacemic Baclofen

Commercially marketed baclofen (Sigma Chemical Co., St. Louis, Mo.) is a50:50 racemic mixture of the R- and S-isomers. In order to betterunderstand the binding affinity of racemic baclofen the Side EffectDatabase (SED) was licensed from Novascreen Biosciences Corporation(Hanover, Md.). The Side Effect Database includes 76 molecular targetsscreened against 10 μM racemic baclofen in duplicate. These targets maybe key mediators of side effects of baclofen, off-target effects andtherapeutic targets. According to the Side Effect Database, baclofen wasfound to be selective for GABA-B and to less than about 50% binding at10 μM to the other 75 molecular targets.

The experiments described herein in these preclinical studiesdemonstrate efficacy for racemic baclofen on a wide range ofpharmacologic, physiologic and behavioral assays. Racemic baclofenreduces marble burying behavior in Fmr1 knockout mice (FIG. 1). Marbleburying behavior is believed to reflect anxiety related,obsessive/compulsive and preservative responding and, thus, mimicssymptoms commonly observed in subjects with fragile X syndrome and otherdisorders of brain development.

R-Baclofen

The R-isomer of baclofen (R-baclofen) is a more potent GABA-B agonistthan the S-isomer. The binding affinity for the R-(about 99% R-baclofen)and S-(about 99% S-baclofen) isomers of baclofen (purchased from SigmaChemical Co., St. Louis, Mo.) was assessed. Both R- and S-baclofen wereassayed at 10 μM in duplicate against 74 molecular targets (29neurotransmitter related targets, 1 steroid, 3 ion channels, 1 secondmessenger, 4 growth factors/hormones, 13 brain/gut peptides, 12 generalenzymes, 9 kinases, and 2 cell based and functional targets). Testingconfirmed that R- and S-baclofen are selective agonists of GABA-B andalso that the R-isomer is a more potent GABA-B agonist than the S-isomer(Table 3). As shown in Table 3 GABA(B) binding assay was performed usingrat cortical membranes. IC50 and Ki values indicate that R-baclofen isabout 10 to about 15 times more potent than S-baclofen and R-/S-baclofenis intermediate in potency.

TABLE 3 Isomer(s) IC50 Ki R-baclofen 1.23 × 10⁻⁶ 6.24 × 10⁻⁷ S-baclofen1.66 × 10⁻⁵ 8.59 × 10⁻⁶ R-/S-baclofen 2.96 × 10⁻⁶ 1.51 × 10⁻⁶

Dose-response relationships for racemic (R-/S-) baclofen and each of thesingle isomers (R- or S-baclofen) on marble burying behavior wasassessed. R-baclofen was more potent than S-baclofen as an inhibitor ofmarble-burying behavior (FIGS. 2 and 3). Marble burying behavior isbelieved to reflect anxiety related, obsessive/compulsive andpreservative behavior and thus mimic symptoms commonly observed insubjects with fragile X syndrome (FXS) and other disorders of braindevelopment.

R-baclofen is more potent for inhibition of audiogenic seizures thanS-baclofen (FIG. 4). Increased susceptibility to audiogenic seizures inFmr1 knockout (KO) mice is believed to model the increased prevalence ofseizure disorders in subjects with fragile X syndrome.

Marble Burying Assay Experimental Aim

The goal of the experiment was to determine if marble-burying behavioris reduced following administration of the GABA-B receptor agonistR-baclofen and/or S-baclofen. In these experiments, Fmr1 KO micereceived an i.p. injection of either R-baclofen or S-baclofen and weretested for marble-burying behavior.

Results

The results of the experiment demonstrate that R-baclofen and S-baclofenalter marble-burying behavior in Fmr1 KO mice. There was a significantdose-related alteration in marble burying behavior in Fmr1 KO mice thatreceived an i.p. injection of R-baclofen 1 hr. before testing.Specifically, Fmr1 KO mice that received a dose of 10 mg/kg buriedsignificantly less marbles than mice that received 0, 0.3, 1, 3, or 6mg/kg. There was also a significant dose-related alteration in marbleburying behavior in Fmr1 KO mice that received an i.p. injection ofS-baclofen 1 hr. before testing. Specifically, mice that received 1.0mg/kg buried significantly more marbles than 0.0 mg/kg treated mice. Inaddition, mice that received 50 mg/kg buried less marbles then micereceiving 0, 0.3, 1, 6 or 30 mg/kg S-baclofen.

Conclusions

The findings from this experiment indicate that there is a dose relatedreduction in marble burying behavior in Fmr1 KO mice treated withR-baclofen indicating that R-baclofen reduces the types ofanxiety-like/obsessive/repetitive behaviors assessed in this assay. Inaddition, S-baclofen altered marble-burying behavior in a dose relatedmanner, however, at the 1 mg/kg dose. Fmr1 KO mice actually buried moremarbles, suggesting that this dose may have an effect opposite to thedesired effect. Fmr1 KO mice that received about a 50 mg/kg dose, buriedfewer marbles indicating that this high dose reduces this typeanxiety-like/obsessive/repetitive behaviors assessed in this assay.These data indicate that R-baclofen may be more suitable than S-baclofenfor reducing this type of anxiety-like/obsessive/repetitive behaviorssimulated by the marble burying test.

Fragile X (Fmr1), Knock Out (KO) Mice

Fmr1 KO mice on a C57BL/6J (9 generations) genetic background wereprovided by The Jackson Laboratory (Bar Harbor, Me.). C57BL/6J wasbackcrossed to establish N11 generation Fmr1 mice. All mice for thecurrent study were generated by mating Fmr1 heterozygous female micewith Fmr1 wild-type male mice. Only male Fmr1 KO (Fmr1^(−/y)) mice weretested in this study. Mice were housed 2-5 per cage in a room with a 12hr light: dark cycle (lights on at 6 AM, off at 6 PM) with access tofood and water ad libitum. Male mice that were 2-4 months of age (20-30grams) were used for all experiments. In general, behavioral testing wasperformed between 9 AM and 3 PM. At the start of testing the mice were3-4 months of age. An experimenter who was blind to the genotypes of themice conducted the experiments.

Animals were genotyped by standard PCR techniques. For detection of theFmr1 WT allele (527 bp product), PCR was performed on DNA from tailswith primers Fmr1_S1 (5′GTGGTTAGCTAAAGTGAGGATGAT-3′; SEQ ID NO: 1) andFmr1_S2 (5′CAGGTTTGTTGGGATTAACAGATC-3′; SEQ ID NO: 2). The Fmr1 KOallele (501 bp product) was detected by PCR with the Fmr1_(—)51 primerand primer Fmr1_N2 (5′TGGGCTCTATGGCTTCTGA-3′; SEQ ID NO: 3) which bindsto a Neo cassette that replaced exon 5 of the Fmr1 gene. Cycleconditions were identical for both S1/S2 and S1/N2 combinations: 2 minat 94° C., 30s at 55° C., 60s at 72° C.), 10 min at 72° C. usingstandard PCR reagents.

Methods

A standard mouse cage was filled with 10 cm of corn-cob bedding. Twenty(20) small (1.5-2 cm) black marbles was placed equidistant (about 1-2 cmapart) on top of the bedding. A mouse was placed in the cage and allowedto explore and bury the marbles. After about 20 minutes the mouse wasremoved and the number of marbles buried (a marble is said to be“buried” if more than 50% of it is under the bedding) was recorded.

Baclofen and placebo were administered to the mice one hour prior totraining, by intraperitoneal (i.p.) injections, in a volume of 0.1 ml/10mg body weight.

Mice were injected (i.p.) with a dose of R(+)- or S(−)-baclofen one hourbefore testing. Each mouse was injected with a dose of R or S beforetesting. The order of treatment (e.g., R followed by S, or S followed byR) was balanced, and the dose was randomly assigned for each drug. Therewere at least 3 days between tests.

At the time of the test, a mouse was placed at an end of the cagecontaining marbles and allowed 20 minutes to bury marbles. After the20-minute test, the mice were removed and the marbles buried werecounted. A marble was identified as ‘buried’ if at least about 50% of itwas covered with bedding. After testing mice were returned to their homecage. The following number (N) of mice were used for the variousR(+)-baclofen doses: N=16, 0 mg/kg; N=15, 0.3 mg/kg; N=15, 1.0 mg/kg;N=10, 3.0 mg/kg; N=13, 6.0 mg/kg; N=10, 10 mg/kg. The following number(N) of mice were used for the various S(−)-baclofen doses: N=15, 0mg/kg; N=13, 0.3 mg/kg; N=14, 1.0 mg/kg; N=12, 6.0 mg/kg; N=11, 30.0mg/kg; N=14, 50 mg/kg.

Marbles buried were manually scored on a data sheet by an experimenterthat was blind to the genotype and treatment. The data were thenmanually entered into a computer-spreadsheet.

The data were analyzed with a two-way (dose X treatment order) ANOVA.

Significant main effects of dose were then analyzed using Least Squarefollow-up comparisons. Statistical analyses were analyzed using SPSS11.0.

Results Racemic Baclofen

Administration of racemic baclofen (6 mg/kg, 12 mg/kg) to fragile Xknockout mice reduced marble burying behavior in a dose dependent manner(FIG. 1).

R(+)-Baclofen

FIG. 2 shows that there was a significant (p<0.005) dose-relatedalteration in marble burying behavior in Fmr1 KO mice that received ani.p. injection of R-baclofen one hour before testing. Specifically, Fmr1KO mice that received a dose of 10 mg/kg buried significantly less(p<0.05) marbles then mice that received 0, 0.3, 1, 3, or 6 mg/kg. Theeffect of treatment order was not statistically significant (p>0.05).

S(−)-Baclofen

FIG. 3 shows that there was also a significant (p<0.005) dose-relatedalteration in marble burying behavior in Fmr1 KO mice that received ani.p. injection of S-baclofen one hour before testing. Specifically, micethat received 1.0 mg/kg buried significantly (p<0.05) more marbles than0.0 mg/kg treated mice. In addition, mice that received 50 mg/kg buriedsignificantly less (p's<0.05) marbles then mice receiving 0, 0.3, 1, 6,or 30 mg/kg S-baclofen. The effect of treatment order was notstatistically significant (p>0.05).

Conclusion

The findings from this experiment indicate that there is a dose relatedreduction in marble burying behavior in Fmr1 KO mice treated withracemic baclofen. When administered separately, R-baclofen reduces thetypes of anxiety-like/obsessive/repetitive behaviors assessed in thisassay. S-baclofen also altered marble-burying behavior in a dose relatedmanner, however, at the 1 mg/kg dose, Fmr1 KO mice actually buried moremarbles, suggesting that this dose may have an effect opposite to thedesired effect. Fmr1 KO mice that received a 50 mg/kg dose, however, didbury fewer marbles indicating that this high dose reduces the typesanxiety-like/obsessive/repetitive behaviors assessed in this assay.Together the findings suggest that R-baclofen may be more suitable thanS-baclofen for reducing the type of anxiety-like/obsessive/repetitivebehaviors simulated by the marble test.

Audiogenic Seizure Assay Experimental Aim

The goal of the experiment was to determine if the sensitivity toaudiogenic seizures in are reduced in Fmr1 KO mice followingadministration of the GABA-B receptor agonist R-baclofen and/orS-baclofen. In these experiments, Fmr1 KO mice received an i.p.injection of either R-baclofen or S-baclofen and tested for theaudiogenic seizures.

Results

The results of the experiment demonstrate that R(+)-baclofen, but notS(−)-baclofen, reduces audiogenic seizures in Fmr1 KO mice. About 70-80%of vehicle-treated and S(−)-baclofen-treated (3 mg/kg) Fmr1 KO micedisplay an audiogenic seizure. In contract, only 33% of Fmr1 KO micetreated with 3 mg/kg R(+)baclofen display seizures.

Conclusions

The findings show that that R(+)-baclofen, but not S(−)-baclofen,reduced audiogenic seizures in Fmr1 KO mice and that R-baclofen is moreeffective than S-baclofen for reducing this type ofenvironmentally-induced seizure in Fmr1 KO mice.

Methods

The methods employed in audiogenic seizure experiments as previouslydescribed (Yan, Q. J., et al., Genes Brain Behav. 3:337-359 (2004); Yan,Q. J., et al., Neuropharm. 49:1053-1066 (2005)). Briefly, Fmr1 knockoutmice were treated i.p. with either vehicle, R-baclofen or S-baclofenabout 60 minutes prior to the assay. Mice were exposed to a highintensity sound and then observed for occurrence of seizures. Theprimary endpoint was frequency of status epilepticus, a sustained tonicseizure most often resulting in respiratory arrest and death.

Test and control articles were administered to the mice one hour priorto training, via intraperitoneal (i.p.) injections, in a volume of 0.1ml/10 g body weight.

Mice were injected (i.p.) with a dose of R(+)- or S(−)-baclofen 45-minbefore testing. Each mouse was injected with a dose of R or S beforetesting. Mice used for this study were experimentally naive.

Two-three mice were placed into a clean cage with bedding andtransferred from their holding cage into a sound attenuated chamber. Thecage was placed under a lid that contained two Radio Shack PersonalAlarms. After 1 min the alarm sound was turned on for two minutes. Afterthis two-minute exposure mice were given another minute of no soundfollowed by a second two-minute alarm. The presence of seizures asdefined by ‘non-startling’ wild-running or tonic/clonic seizures wererecorded. In our test protocol, mice do not display a seizure during thefirst alarm period.

The following number (N) of mice were used for the study: 0 mg/kg N=10;3 mg/kg R(+)-baclofen N=9; and 3 mg/kg S(−)-baclofen N=9.

The presence of seizures as defined by ‘non-startling’ wild-running ortonic/clonic seizures were recorded. In addition, the latency towild-running and/or tonic/clonic seizures was recorded. The percentageof mice displaying seizures was analyzed using SPSS 11.0.

Results

R-baclofen (3 mg/kg) significantly prevented induction of audiogenicseizures whereas S-baclofen at the same dose was no more effective thanvehicle (FIG. 4).

FIG. 4 shows that about 70% of vehicle-treated Fmr1 KO mice displayedaudiogenic seizures. Similarly, about 78% of Fmr1 KO mice treated withabout 3 mg/kg S(−)-baclofen displayed seizures. In contract, only about33% of Fmr1 KO mice treated with 3 mg/kg R(+)-baclofen displayedseizures.

Conclusion

These findings suggest that R-baclofen is likely to be more effectivethan S-baclofen for reducing this type of environmentally-inducedseizure in Fmr1 KO mice.

Open Field Testing Experimental Aim

The goal of the experiment was to determine if open-field activity inFmr1 KO mice is altered following administration of the GABA-B receptoragonist R-baclofen and/or S-baclofen. In these experiments, Fmr1 KO micereceived an i.p. injection of either R-baclofen or S-baclofen and testedfor open-field activity.

Results

The results of the experiment demonstrate that R(+)-baclofen andS(−)-baclofen reduced open-field activity in Fmr1 KO mice. Relative tovehicle-treated wild type (WT) littermate controls, vehicle-treated Fmr1KO mice were significantly more active in the open-field as measured bytotal activity. There was a significant dose-related reduction inexploratory activity as measured by total distance in Fmr1 KO mice thatreceived an i.p. injection of R(+)- or S(−)-baclofen 1 hr beforetesting. Specifically, Fmr1 KO mice that received a dose of 6 mg/kgR(+)-baclofen were less active (reduced total distance) compared to Fmr1KO mice that received vehicle. Similarly, Fmr1 KO mice that received adose of 50 mg/kg R(+)-baclofen were less active (reduced total distance)compared to Fmr1 KO mice that received vehicle.

Conclusions

These data show that there was a dose related reduction in exploratoryactivity in Fmr1 KO mice treated with R(+)- or S(−)-baclofen. Similar toindividuals with fragile X syndrome, male Fmr1-deficient mice were moreactive, but this increased activity as measured by the total distancetraveled in the open-field arena, can be normalized by baclofen. Thedata suggest that the dose required for S-baclofen that reducesexploratory activity in Fmr1 KO mice is greater than that required forR-baclofen-treated mice. Thus, R-baclofen may be more effective thanS-baclofen for reducing the type of increased activity stimulated by theopen-field test.

Methods

Test and control articles were administered to the mice one hour priorto training, via intraperitoneal (i.p.) injections, in a volume of 0.1ml/10 g body weight.

Mice were injected (i.p.) with a dose of R(+)- or S(−)-baclofen one hourbefore testing. Each mouse was injected with a dose of R or S beforetesting. The order of treatment (e.g. R followed by S, or S followed byR) was balanced, and the dose was randomly assigned for each drug. Therewere at least 3 days between tests. Mice used for this experiment hadbeen previously tested approximately one week earlier on themarble-burying test following treatment with R(+)- and S(−)-baclofen.

Mice were placed into the center of a clear Plexiglas (40 cm×40 cm×30cm) open-field arena and allowed to explore for 30 minutes. Bright,overhead lighting provided approximately 800 lux of illumination insidethe arenas. White noise was present at approximately 55 dB inside thearenas. Total distance traveled data during the 30 minute test werecollected in two-min intervals by a computer-operated Digiscan opticalanimal activity system (Accuscan Electronics), but the data for the full30-min test were analyzed.

The following number (N) of mice were used for the various R(+)-baclofendoses: N=12, 0 mg/kg; N=13, 1.0 mg/kg; N=13, 6.0 mg/kg. The following Nwere used for the various S(−)-baclofen doses: N=12, 0 mg/kg; N=14, 1.0mg/kg; N=12, 50 mg/kg. The N for the WT littermate controls were:R(+)-baclofen vehicle-treatment N=14; S(−)-baclofen vehicle-treatmentN=16.

Open-field activity data were analyzed using a two-step process. First,the data from vehicle-treated WT and Fmr1 KO littermates were analyzedusing a one-way ANOVA. Next, the Fmr1 KO data for the three doses ofeach compound were analyzed to determine if the treatment significantlyalter the behavior of the Fmr1 KO mice. Statistical analyses wereanalyzed using SPSS 11.0

Results R(+)-Baclofen

FIG. 5 shows that there was a significant (p<0.001) increase inlocomotor activity in vehicle-treated Fmr1 KO mice compared tovehicle-treated WT controls. In addition, there was a dose-relatedalteration in total distance traveled in Fmr1 KO mice that received ani.p. injection of R-baclofen 1 hr before testing. Fmr1 KO mice thatreceived a dose of 6 mg/kg were significantly less active (p=0.018) thenmice than vehicle-treated Fmr1 KO mice.

S(−)-Baclofen

FIG. 5 shows that there was a significant (p<0.05) increase in locomotoractivity in vehicle-treated Fmr1 KO mice compared to vehicle-treatedwild type (WT) controls. In addition, there was a dose-relatedalteration in total distance traveled in Fmr1 KO mice that received ani.p. injection of S(−)-baclofen 1 hr before testing. Specifically, Fmr1KO mice that received a dose of 50 mg/kg were significantly less active(p=0.021) then mice than vehicle-treated Fmr1 KO mice.

Conclusions

These data show there is a dose related reduction in locomotor activityin Fmr1 KO mice treated with R(+)-baclofen indicating that R(+)-baclofenreduces Fmr1 KO hyperactivity as assessed in this assay. In addition,S-baclofen reduced Fmr1 KO activity in a dose related manner. A lowerdose of R(+)-baclofen was effective at reducing Fmr1 KO hyperactivityrelative to S(−)-baclofen. R(+)-baclofen may be more suitable thanS(−)-baclofen for reducing the type of hyperactivity in Fmr1 KO micestimulated by the open-field test.

Pre-Clinical Summary

R-baclofen was more than 10-fold more potent than S-baclofen as a GABA-Bagonist (Table 3) and also more potent for inhibition of marble-buryingbehavior (FIGS. 2 and 3). Similarly, R-baclofen is more potent forinhibition of audiogenic seizures than S-baclofen (FIG. 4) and openfield testing (FIG. 5).

Example 7 Treatment of Fragile X Knock Out Mice with a M1 MuscarinicReceptor Antagonist

Dicyclomine reduces marble burying behavior in Fmr1 knockout mice (FIG.6). Marble burying behavior is believed to reflect anxiety related,obsessive/compulsive and preservative responding and thus mimic symptomscommonly observed in subjects with fragile X syndrome and otherdisorders of brain development. Similarly, dicyclomine inhibitedaudiogenic seizures in Fmr1 knockout mice (FIG. 7). Increasedsusceptibility to audiogenic seizures in Fmr1 knockout mice is believedto model the increased prevalence of seizure disorders in subjects withFXS.

Marble Burying Assay Methods

Fmr1 KO mice were bred on a C57BL/6J genetic background. Only male Fmr1KO (Fmr1−/y) mice were tested in this study. A standard mouse cage wasfilled with 10 cm of corn-cob bedding. Small (1.5-2 cm) black marbleswere placed equidistant on top of the bedding. A mouse was placed inthis cage and allowed to explore and bury the marbles. After about 20minutes the mouse was removed and the number of marbles buried (a marblewas considered ‘buried’ if more than about 50% of the marble under thebedding) was recorded. Mice were treated with dicyclomine about 60minutes before the test.

Results

Fmr1 knockout mice in this background strain buried more marbles thanwild type (wt) littermates. Administration of dicyclomine reduced marbleburying behavior in a dose dependent manner (FIG. 6).

Conclusion

These data show there is a dose related reduction in marble buryingbehavior in Fmr1 KO mice treated with dicyclomine. Dicyclomine reducedthe types of anxiety-like/obsessive/repetitive behaviors assessed inthis assay.

Audiogenic Seizure Assay Methods

The methods employed are described above. Briefly, Fmr1 knockout micewere treated i.p. with either vehicle or dicyclomine about 60 minutesprior to the assay. Mice were exposed to a high intensity sound and thenobserved for occurrence of seizures. The primary endpoint was frequencyof status epilepticus, a sustained tonic seizure most often resulting inrespiratory arrest and death.

Results

Dicyclomine significantly prevented induction of audiogenic seizures(FIG. 7).

Conclusion

These data show that dicyclomine effectively rescues seizure in Fmr1 KOmice.

EQUIVALENTS

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

1. A method of improving a social domain in a human having fragile Xsyndrome, comprising the step of administering to the human acomposition that includes a therapeutically effective amount of at leastone gamma-aminobutyric acid agonist.
 2. The method of claim 1, whereinthe composition administered to the human includes a gamma-aminobutyricacid (GABA) agonist is a GABA(B) agonist.
 3. The method of claim 2,wherein the GABA(B) agonist administered to the human includes baclofen.4. The method of claim 3, wherein the baclofen administered to the humanis at least about 70 mole percent R-baclofen, at least about 80 molepercent R-baclofen, at least about 85 mole percent R-baclofen, at leastabout 90 mole percent R-baclofen, at least about 95 mole percentR-baclofen or at least about 99 mole percent R-baclofen.
 5. The methodof claim 4, wherein the baclofen administered to the human is at leastabout 99 mole percent R-baclofen.
 6. The method of claim 1, furtherincluding administering a Group I mGluR antagonist to the human.
 7. Themethod of claim 6, wherein the mGluR antagonist includes a mGluR5antagonist.
 8. The method of claim 6, wherein the mGluR antagonistincludes a mGluR1 member antagonist.
 9. The method of claim 3, whereinthe baclofen is orally administered to the human.
 10. The method ofclaim 3, wherein the baclofen is administered to the human in a dose ofat least one member selected from the group consisting of about 2.5 mg,about 5 mg, about 10 mg, about 15 mg, about 20 mg, about 25 mg, about 30mg, about 40 mg, about 45 mg, about 50 mg and about 100 mg.
 11. Themethod of claim 10, wherein the baclofen is administered in a singledaily dose.
 12. The method of claim 10, wherein the baclofen isadministered to the human in multiple daily doses.
 13. The method ofclaim 12, wherein the baclofen is administered to the human in at leastone member selected from the group consisting of two daily doses, threedaily doses, four daily doses and five daily doses.
 14. The method ofclaim 1, wherein the improvement in the social domain followingadministration of the gamma-aminobutyric acid agonist to the humanfurther includes a decrease in at least one member selected from thegroup consisting of an obsessive compulsive disorder, a sensoryhyperarousal disorder, an anxiety disorder, a seizure disorder,irritability, aggression, startle tremor, repetitive/self-stimulatorybehavior, eye diversion, hand biting, hitting of the head, mood andhitting of others.
 15. The method of claim 1, wherein the improvement inthe social domain following administration of the gamma-aminobutyricacid agonist to the human includes an increase in at least one memberselected from the group consisting of an appropriate response to spokenlanguage, spontaneous attempts to interact, eye contact, motivation andcalmness.
 16. The method of claim 1, wherein administration of thegamma-aminobutyric acid agonist to the human further improves acommunication domain in the human.
 17. A method of improving acommunication domain in a human having fragile X syndrome, comprisingthe step of administering to the human a composition that includes atherapeutically effective amount of at least one gamma-aminobutyric acidagonist.
 18. A method of improving at least one member selected from thegroup consisting of a social domain and a communication domain in ahuman having fragile X syndrome, comprising the step of orallyadministering to the human a composition that includes a therapeuticallyeffective amount at least about 90 mole percent R-baclofen in thecomposition.
 19. The method of claim 18, wherein the baclofenadministered to the human is at least about 99 mole percent R-baclofenin the composition.
 20. The method of claim 19, wherein the R-baclofenis administered to the human in a dose of at least one member selectedfrom the group consisting of about 2.5 mg, about 5 mg, about 10 mg,about 15 mg, about 20 mg, about 25 mg, about 30 mg, about 40 mg, about45 mg, about 50 mg and about 100 mg.